api: add status check for modules

64 files changed, 504 insertions, 453 deletions

diff --git a/api/plugin-api.cpp b/api/plugin-api.cpp
index c28b5d4e..eed377b0 100644
--- a/api/plugin-api.cpp
+++ b/api/plugin-api.cpp
@@ -26,6 +26,16 @@ void BaseDialog::closeEvent(QCloseEvent*)
 
 bool ITracker::center() { return false; }
 
+module_status ITracker::status_ok()
+{
+    return module_status();
+}
+
+module_status ITracker::error(const QString& error)
+{
+    return module_status(error);
+}
+
 Metadata::Metadata() {}
 IFilter::IFilter() {}
 IFilterDialog::IFilterDialog() {}
@@ -46,3 +56,14 @@ void BaseDialog::done(int)
 IExtensionDialog::~IExtensionDialog()
 {
 }
+
+bool module_status::is_ok() const
+{
+    return error.isEmpty();
+}
+
+module_status::module_status(const QString& error) : error(error) {}
+
+module_status module_status_mixin::status_ok() { return module_status(); }
+
+module_status module_status_mixin::error(const QString& error) { return module_status(error); }
diff --git a/api/plugin-api.hpp b/api/plugin-api.hpp
index 29f678f3..15a2cc48 100644
--- a/api/plugin-api.hpp
+++ b/api/plugin-api.hpp
@@ -82,8 +82,24 @@ struct OTR_API_EXPORT Metadata
     virtual ~Metadata();
 };
 
+struct OTR_API_EXPORT module_status final
+{
+    QString error;
+
+    bool is_ok() const;
+    module_status(const QString& error = QString());
+};
+
+struct OTR_API_EXPORT module_status_mixin
+{
+    static module_status status_ok();
+    static module_status error(const QString& error);
+
+    virtual module_status check_status() = 0;
+};
+
 // implement this in filters
-struct OTR_API_EXPORT IFilter
+struct OTR_API_EXPORT IFilter : module_status_mixin
 {
     IFilter(const IFilter&) = delete;
     IFilter(IFilter&&) = delete;
@@ -116,7 +132,7 @@ struct OTR_API_EXPORT IFilterDialog : public plugin_api::detail::BaseDialog
     OPENTRACK_DECLARE_PLUGIN_INTERNAL(filter_class, IFilter, metadata_class, dialog_class, IFilterDialog)
 
 // implement this in protocols
-struct OTR_API_EXPORT IProtocol
+struct OTR_API_EXPORT IProtocol : module_status_mixin
 {
     IProtocol();
 
@@ -126,10 +142,8 @@ struct OTR_API_EXPORT IProtocol
 
     // optional destructor
     virtual ~IProtocol();
-    // return true if protocol was properly initialized
-    virtual bool correct() = 0;
     // called 250 times a second with XYZ yaw pitch roll pose
-    // try not to perform intense computation here. if you must, use a thread.
+    // try not to perform intense computation here. use a thread.
     virtual void pose(const double* headpose) = 0;
     // return game name or placeholder text
     virtual QString game_name() = 0;
@@ -159,13 +173,16 @@ struct OTR_API_EXPORT ITracker
     // optional destructor
     virtual ~ITracker();
     // start tracking, and grab a frame to display webcam video in, optionally
-    virtual void start_tracker(QFrame* frame) = 0;
+    virtual module_status start_tracker(QFrame* frame) = 0;
     // return XYZ yaw pitch roll data. don't block here, use a separate thread for computation.
     virtual void data(double *data) = 0;
     // tracker notified of centering
     // returning true makes identity the center pose
     virtual bool center();
 
+    static module_status status_ok();
+    static module_status error(const QString& error);
+
     ITracker(const ITracker&) = delete;
     ITracker(ITracker&&) = delete;
     ITracker& operator=(const ITracker&) = delete;
@@ -187,7 +204,7 @@ struct OTR_API_EXPORT ITrackerDialog : public plugin_api::detail::BaseDialog
 #define OPENTRACK_DECLARE_TRACKER(tracker_class, dialog_class, metadata_class) \
     OPENTRACK_DECLARE_PLUGIN_INTERNAL(tracker_class, ITracker, metadata_class, dialog_class, ITrackerDialog)
 
-struct OTR_API_EXPORT IExtension
+struct OTR_API_EXPORT IExtension : module_status_mixin
 {
     enum event_mask : unsigned
     {
diff --git a/ext-falcon-bms-linear-acc/falcon-bms-ext.hpp b/ext-falcon-bms-linear-acc/falcon-bms-ext.hpp
index 4dd6c5d5..d5d5216f 100644
--- a/ext-falcon-bms-linear-acc/falcon-bms-ext.hpp
+++ b/ext-falcon-bms-linear-acc/falcon-bms-ext.hpp
@@ -8,4 +8,5 @@ struct falcon_bms_acceleration_ext : IExtension
     event_mask hook_types() override;
     falcon_bms_acceleration_ext();
     void process_finished(Pose&p) override;
+    module_status check_status() override { return status_ok(); }
 };
diff --git a/filter-accela/ftnoir_filter_accela.h b/filter-accela/ftnoir_filter_accela.h
index f3fcb6a5..990a9750 100644
--- a/filter-accela/ftnoir_filter_accela.h
+++ b/filter-accela/ftnoir_filter_accela.h
@@ -23,6 +23,7 @@ public:
     void filter(const double* input, double *output) override;
     void center() override { first_run = true; }
     spline spline_rot, spline_pos;
+    module_status check_status() override { return status_ok(); }
 private:
     settings_accela s;
     double last_output[6], deltas[6];
diff --git a/filter-ewma2/ftnoir_filter_ewma2.h b/filter-ewma2/ftnoir_filter_ewma2.h
index f8c77280..4c019bd0 100644
--- a/filter-ewma2/ftnoir_filter_ewma2.h
+++ b/filter-ewma2/ftnoir_filter_ewma2.h
@@ -25,6 +25,7 @@ public:
     ewma();
     void filter(const double *input, double *output) override;
     void center() override { first_run = true; }
+    module_status check_status() override { return status_ok(); }
 private:
     // Deltas are smoothed over the last 1/60sec.
     const double delta_RC = 1./60;
diff --git a/gui/main-window.cpp b/gui/main-window.cpp
index 87a7ad8e..b0f26cbe 100644
--- a/gui/main-window.cpp
+++ b/gui/main-window.cpp
@@ -506,10 +506,6 @@ void MainWindow::start_tracker_()
 
     if (!work->is_ok())
     {
-        QMessageBox::warning(this, tr("Library load error"),
-                             tr("One of libraries failed to load. Check installation."),
-                             QMessageBox::Ok,
-                             QMessageBox::NoButton);
         work = nullptr;
         return;
     }
diff --git a/logic/runtime-libraries.cpp b/logic/runtime-libraries.cpp
index a04da6a2..8feeaaba 100644
--- a/logic/runtime-libraries.cpp
+++ b/logic/runtime-libraries.cpp
@@ -1,13 +1,13 @@
 #include "runtime-libraries.hpp"
 #include "options/scoped.hpp"
+#include <QMessageBox>
 #include <QDebug>
 
-runtime_libraries::runtime_libraries(QFrame* frame, dylibptr t, dylibptr p, dylibptr f) :
-    pTracker(nullptr),
-    pFilter(nullptr),
-    pProtocol(nullptr),
-    correct(false)
+runtime_libraries::runtime_libraries(QFrame* frame, dylibptr t, dylibptr p, dylibptr f)
 {
+    module_status status =
+            module_status_mixin::error(QCoreApplication::translate("module", "Library load failure"));
+
     using namespace options;
 
     with_tracker_teardown sentinel;
@@ -15,15 +15,12 @@ runtime_libraries::runtime_libraries(QFrame* frame, dylibptr t, dylibptr p, dyli
     pProtocol = make_dylib_instance<IProtocol>(p);
 
     if (!pProtocol)
-    {
-        qDebug() << "protocol dylib load failure";
         goto end;
-    }
 
-    if(!pProtocol->correct())
+    if(status = pProtocol->check_status(), !status.is_ok())
     {
-        qDebug() << "protocol load failure";
-        pProtocol = nullptr;
+        status = QCoreApplication::translate("module", "Error occured while loading protocol %1\n\n%2\n")
+                    .arg(p->name).arg(status.error);
         goto end;
     }
 
@@ -36,10 +33,30 @@ runtime_libraries::runtime_libraries(QFrame* frame, dylibptr t, dylibptr p, dyli
         goto end;
     }
 
-    pTracker->start_tracker(frame);
+    if (pFilter)
+        if(status = pFilter->check_status(), !status.is_ok())
+        {
+            status = QCoreApplication::translate("module", "Error occured while loading filter %1\n\n%2\n")
+                     .arg(f->name).arg(status.error);
+            goto end;
+        }
+
+    if (status = pTracker->start_tracker(frame), !status.is_ok())
+    {
+        status = QCoreApplication::translate("module", "Error occured while loading tracker %1\n\n%2\n")
+                 .arg(t->name).arg(status.error);
+        goto end;
+    }
 
     correct = true;
+    return;
+
 end:
-    (void)0;
+    pTracker = nullptr;
+    pFilter = nullptr;
+    pProtocol = nullptr;
+
+    if (!status.is_ok())
+        QMessageBox::critical(nullptr, "Startup failure", status.error, QMessageBox::Cancel, QMessageBox::NoButton);
 }
 
diff --git a/logic/runtime-libraries.hpp b/logic/runtime-libraries.hpp
index cc96f0e7..1105c179 100644
--- a/logic/runtime-libraries.hpp
+++ b/logic/runtime-libraries.hpp
@@ -24,5 +24,5 @@ struct OTR_LOGIC_EXPORT runtime_libraries final
     runtime_libraries(QFrame* frame, dylibptr t, dylibptr p, dylibptr f);
     runtime_libraries() : pTracker(nullptr), pFilter(nullptr), pProtocol(nullptr), correct(false) {}
 
-    bool correct;
+    bool correct = false;
 };
diff --git a/options/base-value.hpp b/options/base-value.hpp
index 7bf83619..f000edb1 100644
--- a/options/base-value.hpp
+++ b/options/base-value.hpp
@@ -28,6 +28,7 @@ class OTR_OPTIONS_EXPORT base_value : public QObject
     using comparator = bool(*)(const QVariant& val1, const QVariant& val2);
     template<typename t>
     using signal_sig = void(base_value::*)(cv_qualified<t>) const;
+
 public:
     bundle get_bundle() { return b; }
     QString name() const { return self_name; }
diff --git a/proto-flightgear/ftnoir_protocol_fg.cpp b/proto-flightgear/ftnoir_protocol_fg.cpp
index 3e0f955c..e1101c0f 100644
--- a/proto-flightgear/ftnoir_protocol_fg.cpp
+++ b/proto-flightgear/ftnoir_protocol_fg.cpp
@@ -25,9 +25,14 @@ void flightgear::pose(const double* headpose) {
     (void) outSocket.writeDatagram(reinterpret_cast<const char*>(&FlightData), sizeof(FlightData), destIP, static_cast<quint16>(s.port));
 }
 
-bool flightgear::correct()
+module_status flightgear::check_status()
 {   
-    return outSocket.bind(QHostAddress::Any, 0, QUdpSocket::ShareAddress | QUdpSocket::ReuseAddressHint);
+    if (outSocket.bind(QHostAddress::Any, 0, QUdpSocket::ShareAddress | QUdpSocket::ReuseAddressHint))
+        return status_ok();
+    else
+        return error(QCoreApplication::translate("flightgear", "Can't bind to [%1.%2.%3.%4]:%5")
+                    .arg(s.ip1).arg(s.ip2).arg(s.ip3).arg(s.ip4)
+                    .arg(s.port));
 }
 
 OPENTRACK_DECLARE_PROTOCOL(flightgear, FGControls, flightgearDll)
diff --git a/proto-flightgear/ftnoir_protocol_fg.h b/proto-flightgear/ftnoir_protocol_fg.h
index 48e5f1c1..31a7660c 100644
--- a/proto-flightgear/ftnoir_protocol_fg.h
+++ b/proto-flightgear/ftnoir_protocol_fg.h
@@ -41,11 +41,9 @@ struct settings : opts {
 class flightgear : public IProtocol
 {
 public:
-    bool correct();
     void pose(const double *headpose);
-    QString game_name() {
-        return QCoreApplication::translate("flightgear", "FlightGear");
-    }
+    QString game_name() { return QCoreApplication::translate("flightgear", "FlightGear"); }
+    module_status check_status() override;
 private:
     settings s;
     flightgear_datagram FlightData;
diff --git a/proto-fsuipc/ftnoir_protocol_fsuipc.cpp b/proto-fsuipc/ftnoir_protocol_fsuipc.cpp
index 959408fe..b5259581 100644
--- a/proto-fsuipc/ftnoir_protocol_fsuipc.cpp
+++ b/proto-fsuipc/ftnoir_protocol_fsuipc.cpp
@@ -144,23 +144,14 @@ void fsuipc::pose(const double *headpose ) {
     prevRotZ = virtRotZ;
 }
 
-bool fsuipc::correct()
+module_status fsuipc::check_status()
 {
-    qDebug() << "correct says: Starting Function";
-
-    //
-    // Load the DLL.
-    //
     FSUIPCLib.setFileName( s.LocationOfDLL );
-    if (FSUIPCLib.load() != true) {
-        qDebug() << "correct says: Error loading FSUIPC DLL";
-        return false;
-    }
-    else {
-        qDebug() << "correct says: FSUIPC DLL loaded.";
-    }
 
-    return true;
+    if (FSUIPCLib.load() != true)
+        return error(QCoreApplication::translate("fsuipc", "Can't load fsuipc at '%1'").arg(s.LocationOfDLL));
+    else
+        return status_ok();
 }
 
 OPENTRACK_DECLARE_PROTOCOL(fsuipc, FSUIPCControls, fsuipcDll)
diff --git a/proto-fsuipc/ftnoir_protocol_fsuipc.h b/proto-fsuipc/ftnoir_protocol_fsuipc.h
index cd2ed9a7..54171ce7 100644
--- a/proto-fsuipc/ftnoir_protocol_fsuipc.h
+++ b/proto-fsuipc/ftnoir_protocol_fsuipc.h
@@ -50,12 +50,9 @@ class fsuipc : public IProtocol
 public:
     fsuipc();
     ~fsuipc() override;
-    bool correct();
+    module_status check_status() override;
     void pose(const double* headpose);
-    QString game_name()
-    {
-        return QCoreApplication::translate("fsuipc", "Microsoft Flight Simulator X");
-    }
+    QString game_name() { return QCoreApplication::translate("fsuipc", "Microsoft Flight Simulator X"); }
 private:
     QLibrary FSUIPCLib;
     double prevPosX, prevPosY, prevPosZ, prevRotX, prevRotY, prevRotZ;
diff --git a/proto-ft/ftnoir_protocol_ft.cpp b/proto-ft/ftnoir_protocol_ft.cpp
index fbfc23d9..d03ca59a 100644
--- a/proto-ft/ftnoir_protocol_ft.cpp
+++ b/proto-ft/ftnoir_protocol_ft.cpp
@@ -192,10 +192,10 @@ void freetrack::set_protocols(bool ft, bool npclient)
         settings_npclient.setValue("Path", "");
 }
 
-bool freetrack::correct()
+module_status freetrack::check_status()
 {
     if (!shm.success())
-        return false;
+        return error("Can't load freetrack memory mapping");
 
     bool use_ft = false, use_npclient = false;
 
@@ -241,7 +241,7 @@ bool freetrack::correct()
     if (use_npclient)
         start_dummy();
 
-    return true;
+    return status_ok();
 }
 
 OPENTRACK_DECLARE_PROTOCOL(freetrack, FTControls, freetrackDll)
diff --git a/proto-ft/ftnoir_protocol_ft.h b/proto-ft/ftnoir_protocol_ft.h
index 43c1c3fc..e2faacf3 100644
--- a/proto-ft/ftnoir_protocol_ft.h
+++ b/proto-ft/ftnoir_protocol_ft.h
@@ -49,7 +49,7 @@ class freetrack : public IProtocol
 public:
     freetrack();
     ~freetrack() override;
-    bool correct();
+    module_status check_status() override;
     void pose( const double *headpose );
     QString game_name() override {
         QMutexLocker foo(&game_name_mutex);
diff --git a/proto-iokit-foohid/iokitprotocol.cpp b/proto-iokit-foohid/iokitprotocol.cpp
index 4af6ad5b..693ce31e 100644
--- a/proto-iokit-foohid/iokitprotocol.cpp
+++ b/proto-iokit-foohid/iokitprotocol.cpp
@@ -20,9 +20,22 @@ IOKitProtocol::IOKitProtocol()
         qWarning("%s\n", qPrintable(joystick->errorMessage()));
 }
 
-bool IOKitProtocol::correct()
+module_status IOKitProtocol::check_status()
 {
-    return joystick && !joystick->hasError();
+    if (!joystick)
+        return QCoreApplication::translate("foohid", "Load failure");
+
+    if (joystick->hasError())
+    {
+        QString msg = joystick->errorMessage();
+
+        if (msg.isEmpty())
+            msg = QCoreApplication::translate("foohid", "Unknown error");
+
+        return error(msg);
+    }
+
+    return status_ok();
 }
 
 static uint8_t valueToStick(FooHIDJoystick *stick, double min, double value, double max)
diff --git a/proto-iokit-foohid/iokitprotocol.h b/proto-iokit-foohid/iokitprotocol.h
index f3f4089f..4c5b13a4 100644
--- a/proto-iokit-foohid/iokitprotocol.h
+++ b/proto-iokit-foohid/iokitprotocol.h
@@ -18,7 +18,7 @@ class IOKitProtocol : public IProtocol
 public:
     IOKitProtocol();
 
-    bool correct() final;
+    module_status check_status() override;
     void pose(const double *headpose) final;
     QString game_name() final;
 
diff --git a/proto-mouse/ftnoir_protocol_mouse.cpp b/proto-mouse/ftnoir_protocol_mouse.cpp
index d03c6c66..80426460 100644
--- a/proto-mouse/ftnoir_protocol_mouse.cpp
+++ b/proto-mouse/ftnoir_protocol_mouse.cpp
@@ -82,9 +82,4 @@ int mouse::get_value(double val, double sensitivity, bool is_rotation)
 
 mouse::mouse() : last_x(0), last_y(0) {}
 
-bool mouse::correct()
-{
-    return true;
-}
-
 OPENTRACK_DECLARE_PROTOCOL(mouse, MOUSEControls, mouseDll)
diff --git a/proto-mouse/ftnoir_protocol_mouse.h b/proto-mouse/ftnoir_protocol_mouse.h
index 4f0bf5a7..99557d17 100644
--- a/proto-mouse/ftnoir_protocol_mouse.h
+++ b/proto-mouse/ftnoir_protocol_mouse.h
@@ -29,7 +29,7 @@ class mouse : public IProtocol
 {
 public:
     mouse();
-    bool correct() override;
+    module_status check_status() override { return status_ok(); }
     void pose( const double *headpose) override;
     QString game_name() override;
 
diff --git a/proto-simconnect/ftnoir_protocol_sc.cpp b/proto-simconnect/ftnoir_protocol_sc.cpp
index c37fa91c..787cf0e3 100644
--- a/proto-simconnect/ftnoir_protocol_sc.cpp
+++ b/proto-simconnect/ftnoir_protocol_sc.cpp
@@ -161,7 +161,7 @@ private:
     bool ok;
 };
 
-bool simconnect::correct()
+module_status simconnect::check_status()
 {
     if (!SCClientLib.isLoaded())
     {
@@ -170,46 +170,39 @@ bool simconnect::correct()
         if (ctx.is_ok())
         {
             SCClientLib.setFileName("SimConnect.dll");
-            if (!SCClientLib.load()) {
-                qDebug() << "simconnect: dll load failed --" << SCClientLib.errorString();
-                return false;
-            }
+            if (!SCClientLib.load())
+                return error(tr("dll load failed -- %1").arg(SCClientLib.errorString()));
         }
         else
-            return false;
+            return error("can't load SDK -- check selected simconnect version");
     }
 
     simconnect_open = (importSimConnect_Open) SCClientLib.resolve("SimConnect_Open");
     if (simconnect_open == NULL) {
-        qDebug() << "simconnect: SimConnect_Open function not found in DLL!";
-        return false;
+        return error("simconnect: SimConnect_Open function not found in DLL!");
     }
     simconnect_set6DOF = (importSimConnect_CameraSetRelative6DOF) SCClientLib.resolve("SimConnect_CameraSetRelative6DOF");
     if (simconnect_set6DOF == NULL) {
-        qDebug() << "simconnect: SimConnect_CameraSetRelative6DOF function not found in DLL!";
-        return false;
+        return error("simconnect: SimConnect_CameraSetRelative6DOF function not found in DLL!");
     }
     simconnect_close = (importSimConnect_Close) SCClientLib.resolve("SimConnect_Close");
     if (simconnect_close == NULL) {
-        qDebug() << "simconnect: SimConnect_Close function not found in DLL!";
-        return false;
+        return error("simconnect: SimConnect_Close function not found in DLL!");
     }
 
     simconnect_calldispatch = (importSimConnect_CallDispatch) SCClientLib.resolve("SimConnect_CallDispatch");
     if (simconnect_calldispatch == NULL) {
-        qDebug() << "simconnect: SimConnect_CallDispatch function not found in DLL!";
-        return false;
+        return error("simconnect: SimConnect_CallDispatch function not found in DLL!");
     }
 
     simconnect_subscribetosystemevent = (importSimConnect_SubscribeToSystemEvent) SCClientLib.resolve("SimConnect_SubscribeToSystemEvent");
     if (simconnect_subscribetosystemevent == NULL) {
-        qDebug() << "simconnect: SimConnect_SubscribeToSystemEvent function not found in DLL!";
-        return false;
+        return error("simconnect: SimConnect_SubscribeToSystemEvent function not found in DLL!");
     }
 
     start();
 
-    return true;
+    return status_ok();
 }
 
 void simconnect::handle()
diff --git a/proto-simconnect/ftnoir_protocol_sc.h b/proto-simconnect/ftnoir_protocol_sc.h
index 151dd741..4174bc0c 100644
--- a/proto-simconnect/ftnoir_protocol_sc.h
+++ b/proto-simconnect/ftnoir_protocol_sc.h
@@ -39,7 +39,7 @@ class simconnect : public IProtocol, private QThread
 public:
     simconnect();
     ~simconnect() override;
-    bool correct();
+    module_status check_status() override;
     void pose(const double* headpose);
     void handle();
     QString game_name() {
diff --git a/proto-udp/ftnoir_ftncontrols.ui b/proto-udp/ftnoir_ftncontrols.ui
index 28f8ccdf..d6a4dfce 100644
--- a/proto-udp/ftnoir_ftncontrols.ui
+++ b/proto-udp/ftnoir_ftncontrols.ui
@@ -9,15 +9,15 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>411</width>
-    <height>169</height>
+    <width>372</width>
+    <height>106</height>
    </rect>
   </property>
   <property name="windowTitle">
    <string>UDP protocol settings</string>
   </property>
   <property name="windowIcon">
-   <iconset resource="../gui/main-facetracknoir.qrc">
+   <iconset resource="../gui/opentrack-res.qrc">
     <normaloff>:/images/facetracknoir.png</normaloff>:/images/facetracknoir.png</iconset>
   </property>
   <property name="layoutDirection">
@@ -26,222 +26,176 @@
   <property name="autoFillBackground">
    <bool>false</bool>
   </property>
-  <layout class="QVBoxLayout" name="_vertical_layout">
-   <item>
-    <layout class="QGridLayout" name="gridLayout">
-     <item row="1" column="4">
-      <widget class="QSpinBox" name="spinIPFourthNibble">
-       <property name="maximumSize">
-        <size>
-         <width>60</width>
-         <height>16777215</height>
-        </size>
-       </property>
-       <property name="maximum">
-        <number>255</number>
-       </property>
-       <property name="singleStep">
-        <number>1</number>
-       </property>
-      </widget>
-     </item>
-     <item row="1" column="1">
-      <widget class="QSpinBox" name="spinIPFirstNibble">
-       <property name="maximumSize">
-        <size>
-         <width>60</width>
-         <height>16777215</height>
-        </size>
-       </property>
-       <property name="maximum">
-        <number>255</number>
-       </property>
-       <property name="singleStep">
-        <number>1</number>
-       </property>
-      </widget>
-     </item>
-     <item row="1" column="2">
-      <widget class="QSpinBox" name="spinIPSecondNibble">
-       <property name="maximumSize">
-        <size>
-         <width>60</width>
-         <height>16777215</height>
-        </size>
-       </property>
-       <property name="maximum">
-        <number>255</number>
-       </property>
-       <property name="singleStep">
-        <number>1</number>
-       </property>
-      </widget>
-     </item>
-     <item row="1" column="3">
-      <widget class="QSpinBox" name="spinIPThirdNibble">
-       <property name="maximumSize">
-        <size>
-         <width>60</width>
-         <height>16777215</height>
-        </size>
-       </property>
-       <property name="maximum">
-        <number>255</number>
-       </property>
-       <property name="singleStep">
-        <number>1</number>
-       </property>
-      </widget>
-     </item>
-     <item row="1" column="0">
-      <widget class="QLabel" name="label_4">
-       <property name="text">
-        <string>IP-address remote PC</string>
-       </property>
-      </widget>
-     </item>
-     <item row="2" column="0">
-      <widget class="QLabel" name="label_5">
-       <property name="text">
-        <string>Port-number</string>
-       </property>
-      </widget>
-     </item>
-     <item row="2" column="1">
-      <widget class="QSpinBox" name="spinPortNumber">
-       <property name="minimum">
-        <number>1000</number>
-       </property>
-       <property name="maximum">
-        <number>10000</number>
-       </property>
-      </widget>
-     </item>
-    </layout>
-   </item>
-   <item>
-    <spacer name="verticalSpacer">
-     <property name="orientation">
-      <enum>Qt::Vertical</enum>
+  <layout class="QGridLayout" name="gridLayout_2">
+   <item row="1" column="0">
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Minimum" vsizetype="Maximum">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
      </property>
-     <property name="sizeHint" stdset="0">
-      <size>
-       <width>20</width>
-       <height>40</height>
-      </size>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
      </property>
-    </spacer>
-   </item>
-   <item>
-    <layout class="QVBoxLayout" name="verticalLayout">
-     <item>
-      <widget class="QLabel" name="label">
-       <property name="text">
-        <string>Enter IP-address and port-number for the remote PC.</string>
-       </property>
-       <property name="wordWrap">
-        <bool>true</bool>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <widget class="QLabel" name="label_3">
-       <property name="text">
-        <string>Remember: you may have to change firewall-settings too!</string>
-       </property>
-      </widget>
-     </item>
-    </layout>
+    </widget>
    </item>
-   <item>
-    <layout class="QHBoxLayout" name="horizontalLayout">
-     <item>
-      <spacer name="horizontalSpacer_2">
-       <property name="orientation">
-        <enum>Qt::Horizontal</enum>
-       </property>
-       <property name="sizeHint" stdset="0">
-        <size>
-         <width>40</width>
-         <height>20</height>
-        </size>
-       </property>
-      </spacer>
-     </item>
-     <item>
-      <layout class="QHBoxLayout" name="horizontalLayout_2">
-       <property name="sizeConstraint">
-        <enum>QLayout::SetDefaultConstraint</enum>
-       </property>
-       <item>
-        <widget class="QPushButton" name="btnOK">
-         <property name="sizePolicy">
-          <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
-           <horstretch>0</horstretch>
-           <verstretch>0</verstretch>
-          </sizepolicy>
-         </property>
-         <property name="minimumSize">
-          <size>
-           <width>100</width>
-           <height>0</height>
-          </size>
-         </property>
-         <property name="maximumSize">
-          <size>
-           <width>100</width>
-           <height>16777215</height>
-          </size>
-         </property>
-         <property name="text">
-          <string>OK</string>
-         </property>
-        </widget>
-       </item>
-       <item>
-        <widget class="QPushButton" name="btnCancel">
-         <property name="sizePolicy">
-          <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
-           <horstretch>0</horstretch>
-           <verstretch>0</verstretch>
-          </sizepolicy>
+   <item row="0" column="0">
+    <widget class="QFrame" name="frame">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Minimum" vsizetype="Maximum">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <layout class="QGridLayout" name="gridLayout">
+      <property name="leftMargin">
+       <number>0</number>
+      </property>
+      <property name="topMargin">
+       <number>0</number>
+      </property>
+      <property name="rightMargin">
+       <number>0</number>
+      </property>
+      <property name="horizontalSpacing">
+       <number>22</number>
+      </property>
+      <item row="0" column="1">
+       <widget class="QFrame" name="frame_2">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Minimum" vsizetype="Maximum">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="frameShape">
+         <enum>QFrame::NoFrame</enum>
+        </property>
+        <layout class="QHBoxLayout" name="horizontalLayout">
+         <property name="spacing">
+          <number>12</number>
          </property>
-         <property name="minimumSize">
-          <size>
-           <width>100</width>
-           <height>0</height>
-          </size>
+         <property name="leftMargin">
+          <number>0</number>
          </property>
-         <property name="maximumSize">
-          <size>
-           <width>100</width>
-           <height>16777215</height>
-          </size>
+         <property name="topMargin">
+          <number>0</number>
          </property>
-         <property name="text">
-          <string>Cancel</string>
+         <property name="bottomMargin">
+          <number>0</number>
          </property>
-        </widget>
-       </item>
-      </layout>
-     </item>
-     <item>
-      <spacer name="horizontalSpacer">
-       <property name="orientation">
-        <enum>Qt::Horizontal</enum>
-       </property>
-       <property name="sizeType">
-        <enum>QSizePolicy::Fixed</enum>
-       </property>
-       <property name="sizeHint" stdset="0">
-        <size>
-         <width>10</width>
-         <height>20</height>
-        </size>
-       </property>
-      </spacer>
-     </item>
-    </layout>
+         <item>
+          <widget class="QSpinBox" name="spinIPFirstNibble">
+           <property name="maximumSize">
+            <size>
+             <width>60</width>
+             <height>16777215</height>
+            </size>
+           </property>
+           <property name="maximum">
+            <number>255</number>
+           </property>
+           <property name="singleStep">
+            <number>1</number>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QSpinBox" name="spinIPSecondNibble">
+           <property name="maximumSize">
+            <size>
+             <width>60</width>
+             <height>16777215</height>
+            </size>
+           </property>
+           <property name="maximum">
+            <number>255</number>
+           </property>
+           <property name="singleStep">
+            <number>1</number>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QSpinBox" name="spinIPThirdNibble">
+           <property name="maximumSize">
+            <size>
+             <width>60</width>
+             <height>16777215</height>
+            </size>
+           </property>
+           <property name="maximum">
+            <number>255</number>
+           </property>
+           <property name="singleStep">
+            <number>1</number>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QSpinBox" name="spinIPFourthNibble">
+           <property name="maximumSize">
+            <size>
+             <width>60</width>
+             <height>16777215</height>
+            </size>
+           </property>
+           <property name="maximum">
+            <number>255</number>
+           </property>
+           <property name="singleStep">
+            <number>1</number>
+           </property>
+          </widget>
+         </item>
+        </layout>
+       </widget>
+      </item>
+      <item row="1" column="1">
+       <widget class="QSpinBox" name="spinPortNumber">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Maximum" vsizetype="Maximum">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="minimum">
+         <number>1024</number>
+        </property>
+        <property name="maximum">
+         <number>65535</number>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="0">
+       <widget class="QLabel" name="label_4">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Minimum" vsizetype="Maximum">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="text">
+         <string>Remote IP address</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="0">
+       <widget class="QLabel" name="label_5">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Minimum" vsizetype="Maximum">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="text">
+         <string>Port</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </widget>
    </item>
   </layout>
  </widget>
@@ -251,13 +205,28 @@
   <tabstop>spinIPThirdNibble</tabstop>
   <tabstop>spinIPFourthNibble</tabstop>
   <tabstop>spinPortNumber</tabstop>
-  <tabstop>btnOK</tabstop>
-  <tabstop>btnCancel</tabstop>
  </tabstops>
  <resources>
-  <include location="../gui/main-facetracknoir.qrc"/>
+  <include location="../gui/opentrack-res.qrc"/>
  </resources>
  <connections/>
+ <designerdata>
+  <property name="gridDeltaX">
+   <number>5</number>
+  </property>
+  <property name="gridDeltaY">
+   <number>5</number>
+  </property>
+  <property name="gridSnapX">
+   <bool>true</bool>
+  </property>
+  <property name="gridSnapY">
+   <bool>true</bool>
+  </property>
+  <property name="gridVisible">
+   <bool>false</bool>
+  </property>
+ </designerdata>
  <slots>
   <slot>startEngineClicked()</slot>
   <slot>stopEngineClicked()</slot>
diff --git a/proto-udp/ftnoir_protocol_ftn.cpp b/proto-udp/ftnoir_protocol_ftn.cpp
index b659e3b5..a1f445f0 100644
--- a/proto-udp/ftnoir_protocol_ftn.cpp
+++ b/proto-udp/ftnoir_protocol_ftn.cpp
@@ -14,21 +14,29 @@
 
 udp::udp()
 {
+    set_dest_address();
+    QObject::connect(s.b.get(), &bundle_::changed, this, &udp::set_dest_address);
 }
 
 void udp::pose(const double *headpose) {
-    int destPort = s.port;
-    QHostAddress destIP(QString("%1.%2.%3.%4").arg(
-                            QString::number(static_cast<int>(s.ip1)),
-                            QString::number(static_cast<int>(s.ip2)),
-                            QString::number(static_cast<int>(s.ip3)),
-                            QString::number(static_cast<int>(s.ip4))));
-    outSocket.writeDatagram((const char *) headpose, sizeof( double[6] ), destIP, destPort);
+    outSocket.writeDatagram((const char *) headpose, sizeof(double[6]), dest_ip, dest_port);
 }
 
-bool udp::correct()
-{   
-    return outSocket.bind(QHostAddress::Any, 0, QUdpSocket::ShareAddress | QUdpSocket::ReuseAddressHint);
+void udp::set_dest_address()
+{
+    dest_port = s.port;
+    dest_ip = QHostAddress((s.ip1.to<unsigned>() & 0xff) << 24 |
+                           (s.ip2.to<unsigned>() & 0xff) << 16 |
+                           (s.ip3.to<unsigned>() & 0xff) << 8  |
+                           (s.ip4.to<unsigned>() & 0xff) << 0  );
+}
+
+module_status udp::check_status()
+{
+    if (outSocket.bind(QHostAddress::Any, 0, QUdpSocket::ShareAddress | QUdpSocket::ReuseAddressHint))
+        return status_ok();
+    else
+        return error(tr("Can't bind socket: %1").arg(outSocket.errorString()));
 }
 
 OPENTRACK_DECLARE_PROTOCOL(udp, FTNControls, udpDll)
diff --git a/proto-udp/ftnoir_protocol_ftn.h b/proto-udp/ftnoir_protocol_ftn.h
index b234cd89..7838f01a 100644
--- a/proto-udp/ftnoir_protocol_ftn.h
+++ b/proto-udp/ftnoir_protocol_ftn.h
@@ -31,11 +31,13 @@ struct settings : opts {
     {}
 };
 
-class udp : public IProtocol
+class udp : public QObject, public IProtocol
 {
+    Q_OBJECT
+
 public:
     udp();
-    bool correct();
+    module_status check_status() override;
     void pose(const double *headpose);
     QString game_name() {
         return QCoreApplication::translate("udp_proto", "UDP over network");
@@ -43,12 +45,19 @@ public:
 private:
     QUdpSocket outSocket;
     settings s;
+
+    QHostAddress dest_ip { 127u << 24 | 1u };
+    unsigned short dest_port = 65535;
+
+private slots:
+    void set_dest_address();
 };
 
 // Widget that has controls for FTNoIR protocol client-settings.
 class FTNControls: public IProtocolDialog
 {
     Q_OBJECT
+
 public:
     FTNControls();
     void register_protocol(IProtocol *) {}
diff --git a/proto-udp/ftnoir_protocol_ftn_dialog.cpp b/proto-udp/ftnoir_protocol_ftn_dialog.cpp
index 70416a69..51ce483c 100644
--- a/proto-udp/ftnoir_protocol_ftn_dialog.cpp
+++ b/proto-udp/ftnoir_protocol_ftn_dialog.cpp
@@ -21,8 +21,8 @@ FTNControls::FTNControls()
     tie_setting(s.ip4, ui.spinIPFourthNibble);
     tie_setting(s.port, ui.spinPortNumber);
 
-    connect(ui.btnOK, SIGNAL(clicked()), this, SLOT(doOK()));
-    connect(ui.btnCancel, SIGNAL(clicked()), this, SLOT(doCancel()));
+    connect(ui.buttonBox, &QDialogButtonBox::accepted, this, &FTNControls::doOK);
+    connect(ui.buttonBox, &QDialogButtonBox::rejected, this, &FTNControls::doCancel);
 }
 
 //
diff --git a/proto-vjoystick/vjoystick.cpp b/proto-vjoystick/vjoystick.cpp
index 557b5e99..9ff64998 100644
--- a/proto-vjoystick/vjoystick.cpp
+++ b/proto-vjoystick/vjoystick.cpp
@@ -125,6 +125,21 @@ vjoystick_proto::~vjoystick_proto()
 {
 }
 
+module_status vjoystick_proto::check_status()
+{
+    switch (h.get_state())
+    {
+    case state_notent:
+        return error("vjoystick #1 doesn't exist");
+    case state_fail:
+        return error("can't initialize vjoystick");
+    case state_success:
+        return status_ok();
+    default:
+        return error("unknown error");
+    }
+}
+
 void vjoystick_proto::pose(const double *pose)
 {
     if (h.get_state() != state_success)
diff --git a/proto-vjoystick/vjoystick.h b/proto-vjoystick/vjoystick.h
index 49302030..0eac2ed2 100644
--- a/proto-vjoystick/vjoystick.h
+++ b/proto-vjoystick/vjoystick.h
@@ -53,7 +53,7 @@ class vjoystick_proto : public IProtocol
 public:
     vjoystick_proto();
     ~vjoystick_proto() override;
-    bool correct() override { return h.get_state() == state_success; }
+    module_status check_status() override;
     void pose( const double *headpose ) override;
     QString game_name() override { return "Virtual joystick"; }
 private:
diff --git a/proto-wine/ftnoir_protocol_wine.cpp b/proto-wine/ftnoir_protocol_wine.cpp
index b1b8ecef..36c01c25 100644
--- a/proto-wine/ftnoir_protocol_wine.cpp
+++ b/proto-wine/ftnoir_protocol_wine.cpp
@@ -54,9 +54,12 @@ void wine::pose( const double *headpose )
     }
 }
 
-bool wine::correct()
+module_status wine::check_status()
 {
-    return lck_shm.success();
+    if (lck_shm.success())
+        return status_ok();
+    else
+        return error(QCoreApplication::translate("wine", "Can't open shared memory mapping"));
 }
 
 OPENTRACK_DECLARE_PROTOCOL(wine, FTControls, wineDll)
diff --git a/proto-wine/ftnoir_protocol_wine.h b/proto-wine/ftnoir_protocol_wine.h
index e996a2c2..d435ffb6 100644
--- a/proto-wine/ftnoir_protocol_wine.h
+++ b/proto-wine/ftnoir_protocol_wine.h
@@ -18,9 +18,11 @@ public:
     wine();
     ~wine() override;
 
-    bool correct() override;
+    module_status check_status() override;
     void pose(const double* headpose) override;
-    QString game_name() override {
+
+    QString game_name() override
+    {
         QMutexLocker foo(&game_name_mutex);
         return connected_game;
     }
diff --git a/tracker-aruco/ftnoir_tracker_aruco.cpp b/tracker-aruco/ftnoir_tracker_aruco.cpp
index 37e34246..a1bde523 100644
--- a/tracker-aruco/ftnoir_tracker_aruco.cpp
+++ b/tracker-aruco/ftnoir_tracker_aruco.cpp
@@ -73,7 +73,7 @@ aruco_tracker::~aruco_tracker()
     camera.release();
 }
 
-void aruco_tracker::start_tracker(QFrame* videoframe)
+module_status aruco_tracker::start_tracker(QFrame* videoframe)
 {
     videoframe->show();
     videoWidget = std::make_unique<cv_video_widget>(videoframe);
@@ -83,6 +83,8 @@ void aruco_tracker::start_tracker(QFrame* videoframe)
     videoframe->setLayout(layout.get());
     videoWidget->show();
     start();
+
+    return status_ok();
 }
 
 void aruco_tracker::getRT(cv::Matx33d& r_, cv::Vec3d& t_)
diff --git a/tracker-aruco/ftnoir_tracker_aruco.h b/tracker-aruco/ftnoir_tracker_aruco.h
index fd42d722..72f52eb8 100644
--- a/tracker-aruco/ftnoir_tracker_aruco.h
+++ b/tracker-aruco/ftnoir_tracker_aruco.h
@@ -65,7 +65,7 @@ struct settings : opts {
 
 class aruco_dialog;
 
-class aruco_tracker : protected QThread, public ITracker
+class aruco_tracker : protected virtual QThread, public ITracker
 {
     Q_OBJECT
     friend class aruco_dialog;
@@ -73,7 +73,7 @@ class aruco_tracker : protected QThread, public ITracker
 public:
     aruco_tracker();
     ~aruco_tracker() override;
-    void start_tracker(QFrame* frame) override;
+    module_status start_tracker(QFrame* frame) override;
     void data(double *data) override;
     void run() override;
     void getRT(cv::Matx33d &r, cv::Vec3d &t);
diff --git a/tracker-freepie-udp/ftnoir_tracker_freepie-udp.cpp b/tracker-freepie-udp/ftnoir_tracker_freepie-udp.cpp
index d24b938c..ab2b5b72 100644
--- a/tracker-freepie-udp/ftnoir_tracker_freepie-udp.cpp
+++ b/tracker-freepie-udp/ftnoir_tracker_freepie-udp.cpp
@@ -104,10 +104,12 @@ void tracker_freepie::run() {
     }
 }
 
-void tracker_freepie::start_tracker(QFrame*)
+module_status tracker_freepie::start_tracker(QFrame*)
 {
     start();
     sock.moveToThread(this);
+
+    return status_ok();
 }
 
 void tracker_freepie::data(double *data)
diff --git a/tracker-freepie-udp/ftnoir_tracker_freepie-udp.h b/tracker-freepie-udp/ftnoir_tracker_freepie-udp.h
index 51a710f8..1b609470 100644
--- a/tracker-freepie-udp/ftnoir_tracker_freepie-udp.h
+++ b/tracker-freepie-udp/ftnoir_tracker_freepie-udp.h
@@ -33,7 +33,7 @@ class tracker_freepie : public ITracker, private QThread
 public:
     tracker_freepie();
     ~tracker_freepie() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
 protected:
     void run() override;
diff --git a/tracker-fusion/fusion.cpp b/tracker-fusion/fusion.cpp
index 07f6483f..0b81b682 100644
--- a/tracker-fusion/fusion.cpp
+++ b/tracker-fusion/fusion.cpp
@@ -22,10 +22,7 @@ static auto get_modules()
     return Modules(OPENTRACK_BASE_PATH + OPENTRACK_LIBRARY_PATH);
 }
 
-fusion_tracker::fusion_tracker() :
-    rot_tracker_data{},
-    pos_tracker_data{},
-    other_frame(new QFrame)
+fusion_tracker::fusion_tracker()
 {
 }
 
@@ -52,11 +49,14 @@ const QString& fusion_tracker::caption()
     return caption;
 }
 
-void fusion_tracker::start_tracker(QFrame* frame)
+module_status fusion_tracker::start_tracker(QFrame* frame)
 {
     assert(!rot_tracker && !pos_tracker);
     assert(!rot_dylib && !pos_dylib);
 
+    QString err;
+    module_status status;
+
     fusion_settings s;
     const QString rot_tracker_name = s.rot_tracker_name().toString();
     const QString pos_tracker_name = s.pos_tracker_name().toString();
@@ -65,14 +65,15 @@ void fusion_tracker::start_tracker(QFrame* frame)
     assert(pos_tracker_name != own_name);
 
     if (rot_tracker_name.isEmpty() || pos_tracker_name.isEmpty())
-        goto fail;
+    {
+        err = tr("Trackers not selected.");
+        goto end;
+    }
 
     if (rot_tracker_name == pos_tracker_name)
     {
-        QMessageBox::warning(nullptr, caption(),
-                            tr("Select different trackers for rotation and position."),
-                            QMessageBox::Close);
-        goto cleanup;
+        err = tr("Select different trackers for rotation and position.");
+        goto end;
     }
 
     {
@@ -95,17 +96,28 @@ void fusion_tracker::start_tracker(QFrame* frame)
     }
 
     if (!rot_dylib || !pos_dylib)
-        goto fail;
+        goto end;
 
     rot_tracker = make_dylib_instance<ITracker>(rot_dylib);
     pos_tracker = make_dylib_instance<ITracker>(pos_dylib);
 
-    pos_tracker->start_tracker(frame);
+    status = pos_tracker->start_tracker(frame);
+
+    if (!status.is_ok())
+    {
+        err = pos_dylib->name + QStringLiteral(":\n    ") + status.error;
+        goto end;
+    }
 
     if (frame->layout() == nullptr)
     {
-        rot_tracker->start_tracker(frame);
+        status = rot_tracker->start_tracker(frame);
         other_frame = nullptr;
+        if (!status.is_ok())
+        {
+            err = rot_dylib->name + QStringLiteral(":\n    ") + status.error;
+            goto end;
+        }
     }
     else
     {
@@ -121,14 +133,11 @@ void fusion_tracker::start_tracker(QFrame* frame)
 
     }
 
-    return;
-
-fail:
-    QMessageBox::warning(nullptr,
-                         caption(), tr("Select rotation and position trackers."),
-                         QMessageBox::Close);
-cleanup:
-    other_frame = nullptr;
+end:
+    if (!err.isEmpty())
+        return error(err);
+    else
+        return status_ok();
 }
 
 void fusion_tracker::data(double *data)
@@ -203,4 +212,4 @@ fusion_settings::fusion_settings() :
 {
 }
 
-OPENTRACK_DECLARE_TRACKER(fusion_tracker, fusion_dialog, fusion_metadata)
\ No newline at end of file
+OPENTRACK_DECLARE_TRACKER(fusion_tracker, fusion_dialog, fusion_metadata)
diff --git a/tracker-fusion/fusion.h b/tracker-fusion/fusion.h
index 28e584da..96a1a496 100644
--- a/tracker-fusion/fusion.h
+++ b/tracker-fusion/fusion.h
@@ -19,7 +19,7 @@ class fusion_tracker : public QObject, public ITracker
 {
     Q_OBJECT
 
-    double rot_tracker_data[6], pos_tracker_data[6];
+    double rot_tracker_data[6] {}, pos_tracker_data[6] {};
 
     std::unique_ptr<QFrame> other_frame;
     std::shared_ptr<dylib> rot_dylib, pos_dylib;
@@ -28,7 +28,7 @@ class fusion_tracker : public QObject, public ITracker
 public:
     fusion_tracker();
     ~fusion_tracker() override;
-    void start_tracker(QFrame*) override;
+    module_status start_tracker(QFrame*) override;
     void data(double* data) override;
 
     static const QString& caption();
diff --git a/tracker-hatire/ftnoir_tracker_hat.cpp b/tracker-hatire/ftnoir_tracker_hat.cpp
index 6e1b6586..29381eaa 100644
--- a/tracker-hatire/ftnoir_tracker_hat.cpp
+++ b/tracker-hatire/ftnoir_tracker_hat.cpp
@@ -43,27 +43,27 @@ void hatire::get_info( int *tps )
         *tps=frame_cnt;
         frame_cnt=0;
 }
-void hatire::start_tracker(QFrame*)
+module_status hatire::start_tracker(QFrame*)
 {
-        CptError=0;
-        frame_cnt=0;
+    CptError=0;
+    frame_cnt=0;
     t.Log("Starting Tracker");
 
     serial_result ret = t.init_serial_port();
 
+    t.start();
+
     switch (ret.code)
     {
     case result_ok:
-        break;
+        return status_ok();
     case result_error:
-        QMessageBox::warning(0, tr("Error"), ret.error, QMessageBox::Ok,QMessageBox::NoButton);
-        break;
+        return error(ret.error);
     case result_open_error:
-        QMessageBox::warning(0, tr("Error"), tr("Unable to open ComPort: %1").arg(ret.error), QMessageBox::Ok,QMessageBox::NoButton);
-        break;
+        return error(tr("Unable to open ComPort: %1").arg(ret.error));
+    default:
+        return error("Unknown error");
     }
-
-    t.start();
 }
 
 void hatire::serial_info()
diff --git a/tracker-hatire/ftnoir_tracker_hat.h b/tracker-hatire/ftnoir_tracker_hat.h
index fa8b8448..45b3f250 100644
--- a/tracker-hatire/ftnoir_tracker_hat.h
+++ b/tracker-hatire/ftnoir_tracker_hat.h
@@ -22,7 +22,7 @@ public:
     hatire();
     ~hatire();
 
-    void start_tracker(QFrame*);
+    module_status start_tracker(QFrame*);
     void data(double *data);
     //void center();
     //bool notifyZeroed();
diff --git a/tracker-hydra/ftnoir_tracker_hydra.cpp b/tracker-hydra/ftnoir_tracker_hydra.cpp
index d1e2fb36..69bb71e9 100644
--- a/tracker-hydra/ftnoir_tracker_hydra.cpp
+++ b/tracker-hydra/ftnoir_tracker_hydra.cpp
@@ -33,9 +33,11 @@ Hydra_Tracker::~Hydra_Tracker()
     sixenseExit();
 }
 
-void Hydra_Tracker::start_tracker(QFrame*)
+module_status Hydra_Tracker::start_tracker(QFrame*)
 {
     sixenseInit();
+
+    return status_ok();
 }
 
 void Hydra_Tracker::data(double *data)
diff --git a/tracker-hydra/ftnoir_tracker_hydra.h b/tracker-hydra/ftnoir_tracker_hydra.h
index 15016e4e..f6b9a099 100644
--- a/tracker-hydra/ftnoir_tracker_hydra.h
+++ b/tracker-hydra/ftnoir_tracker_hydra.h
@@ -16,8 +16,9 @@ class Hydra_Tracker : public ITracker
 public:
     Hydra_Tracker();
     ~Hydra_Tracker();
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
+
 private:
     settings s;
     QMutex mutex;
diff --git a/tracker-joystick/ftnoir_tracker_joystick.cpp b/tracker-joystick/ftnoir_tracker_joystick.cpp
index 498b4e42..42c2214a 100644
--- a/tracker-joystick/ftnoir_tracker_joystick.cpp
+++ b/tracker-joystick/ftnoir_tracker_joystick.cpp
@@ -26,10 +26,6 @@ joystick::~joystick()
 {
 }
 
-void joystick::start_tracker(QFrame*)
-{
-}
-
 void joystick::data(double *data)
 {
     int map[6] = {
diff --git a/tracker-joystick/ftnoir_tracker_joystick.h b/tracker-joystick/ftnoir_tracker_joystick.h
index aea45983..bba4ad3e 100644
--- a/tracker-joystick/ftnoir_tracker_joystick.h
+++ b/tracker-joystick/ftnoir_tracker_joystick.h
@@ -41,7 +41,7 @@ class joystick : public ITracker
 public:
     joystick();
     ~joystick();
-    void start_tracker(QFrame *);
+    module_status start_tracker(QFrame *) { return status_ok(); }
     void data(double *data);
     settings s;
     QString guid;
diff --git a/tracker-pt/ftnoir_tracker_pt.cpp b/tracker-pt/ftnoir_tracker_pt.cpp
index ac514813..5975f701 100644
--- a/tracker-pt/ftnoir_tracker_pt.cpp
+++ b/tracker-pt/ftnoir_tracker_pt.cpp
@@ -153,7 +153,7 @@ void Tracker_PT::set_fov(int value)
     camera.set_fov(value);
 }
 
-void Tracker_PT::start_tracker(QFrame* video_frame)
+module_status Tracker_PT::start_tracker(QFrame* video_frame)
 {
     //video_frame->setAttribute(Qt::WA_NativeWindow);
     preview_size = video_frame->size();
@@ -172,6 +172,8 @@ void Tracker_PT::start_tracker(QFrame* video_frame)
     maybe_reopen_camera();
 
     start(QThread::HighPriority);
+
+    return status_ok();
 }
 
 void Tracker_PT::data(double *data)
diff --git a/tracker-pt/ftnoir_tracker_pt.h b/tracker-pt/ftnoir_tracker_pt.h
index 6c2923c0..ad7f56ff 100644
--- a/tracker-pt/ftnoir_tracker_pt.h
+++ b/tracker-pt/ftnoir_tracker_pt.h
@@ -40,12 +40,13 @@ using namespace types;
 class Tracker_PT : public QThread, public ITracker
 {
     Q_OBJECT
+
     friend class camera_dialog;
     friend class ::TrackerDialog_PT;
 public:
     Tracker_PT();
     ~Tracker_PT() override;
-    void start_tracker(QFrame* parent_window) override;
+    module_status start_tracker(QFrame* parent_window) override;
     void data(double* data) override;
 
     Affine pose();
diff --git a/tracker-pt/ftnoir_tracker_pt_dialog.cpp b/tracker-pt/ftnoir_tracker_pt_dialog.cpp
index 0746a85e..2c3cbd07 100644
--- a/tracker-pt/ftnoir_tracker_pt_dialog.cpp
+++ b/tracker-pt/ftnoir_tracker_pt_dialog.cpp
@@ -63,7 +63,7 @@ TrackerDialog_PT::TrackerDialog_PT()
 
     tie_setting(s.auto_threshold, ui.auto_threshold);
 
-    connect( ui.tcalib_button,SIGNAL(toggled(bool)), this,SLOT(startstop_trans_calib(bool)));
+    connect(ui.tcalib_button,SIGNAL(toggled(bool)), this, SLOT(startstop_trans_calib(bool)));
 
     connect(ui.buttonBox, SIGNAL(accepted()), this, SLOT(doOK()));
     connect(ui.buttonBox, SIGNAL(rejected()), this, SLOT(doCancel()));
diff --git a/tracker-rift-025/ftnoir_tracker_rift_025.cpp b/tracker-rift-025/ftnoir_tracker_rift_025.cpp
index 92ae36ea..8d4a6e8a 100644
--- a/tracker-rift-025/ftnoir_tracker_rift_025.cpp
+++ b/tracker-rift-025/ftnoir_tracker_rift_025.cpp
@@ -41,8 +41,10 @@ rift_tracker_025::~rift_tracker_025()
     System::Destroy();
 }
 
-void rift_tracker_025::start_tracker(QFrame*)
+module_status rift_tracker_025::start_tracker(QFrame*)
 {
+    QString err;
+
     System::Init(Log::ConfigureDefaultLog(LogMask_All));
     pManager = DeviceManager::Create();
     if (pManager != NULL)
@@ -59,29 +61,19 @@ void rift_tracker_025::start_tracker(QFrame*)
                 pSFusion->AttachToSensor(pSensor);
             }
             else
-            {
-                QMessageBox::warning(nullptr,
-                                     QCoreApplication::translate("rift_tracker_025", "Error"),
-                                     QCoreApplication::translate("rift_tracker_025", "Unable to create Rift sensor"),
-                                     QMessageBox::Ok,QMessageBox::NoButton);
-            }
+                err = tr("Unable to create Rift sensor");
 
         }
         else
-        {
-            QMessageBox::warning(nullptr,
-                                 QCoreApplication::translate("rift_tracker_025", "Error"),
-                                 QCoreApplication::translate("rift_tracker_025", "Unable to enumerate Rift tracker"),
-                                 QMessageBox::Ok,QMessageBox::NoButton);
-        }
+            err = tr("Unable to enumerate Rift tracker");
     }
     else
-    {
-        QMessageBox::warning(nullptr,
-                             QCoreApplication::translate("rift_tracker_025", "Error"),
-                             QCoreApplication::translate("rift_tracker_025", "Unable to start Rift tracker"),
-                             QMessageBox::Ok,QMessageBox::NoButton);
-    }
+        err = tr("Unable to start Rift tracker");
+
+    if (err.isEmpty())
+        return status_ok();
+    else
+        return error(err);
 }
 
 
diff --git a/tracker-rift-025/ftnoir_tracker_rift_025.h b/tracker-rift-025/ftnoir_tracker_rift_025.h
index b65d3e56..37ffcdaa 100644
--- a/tracker-rift-025/ftnoir_tracker_rift_025.h
+++ b/tracker-rift-025/ftnoir_tracker_rift_025.h
@@ -21,12 +21,14 @@ struct settings : opts {
     {}
 };
 
-class rift_tracker_025 : public ITracker
+class rift_tracker_025 : public QObject, public ITracker
 {
+    Q_OBJECT
+
 public:
     rift_tracker_025();
     virtual ~rift_tracker_025() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
 private:
     double old_yaw;
diff --git a/tracker-rift-042/ftnoir_tracker_rift_042.cpp b/tracker-rift-042/ftnoir_tracker_rift_042.cpp
index 0e52812d..c8ced38f 100644
--- a/tracker-rift-042/ftnoir_tracker_rift_042.cpp
+++ b/tracker-rift-042/ftnoir_tracker_rift_042.cpp
@@ -36,22 +36,17 @@ rift_tracker_042::~rift_tracker_042()
     ovr_Shutdown();
 }
 
-void rift_tracker_042::start_tracker(QFrame*)
+module_status rift_tracker_042::start_tracker(QFrame*)
 {
     ovr_Initialize();
     hmd = ovrHmd_Create(0);
     if (hmd)
     {
         ovrHmd_ConfigureTracking(hmd, ovrTrackingCap_Orientation | ovrTrackingCap_MagYawCorrection | ovrTrackingCap_Position, ovrTrackingCap_Orientation);
+        return status_ok();
     }
     else
-    {
-        QMessageBox::warning(nullptr,
-                             "Error",
-                             QCoreApplication::translate("rift_tracker_042", "Unable to start Rift tracker: %1").arg(ovrHmd_GetLastError(nullptr)),
-                             QMessageBox::Ok,
-                             QMessageBox::NoButton);
-    }
+        return error(tr("Unable to start Rift tracker: %1").arg(ovrHmd_GetLastError(nullptr)));
 }
 
 
diff --git a/tracker-rift-042/ftnoir_tracker_rift_042.h b/tracker-rift-042/ftnoir_tracker_rift_042.h
index 82081085..630878b9 100644
--- a/tracker-rift-042/ftnoir_tracker_rift_042.h
+++ b/tracker-rift-042/ftnoir_tracker_rift_042.h
@@ -21,12 +21,14 @@ struct settings : opts {
     {}
 };
 
-class rift_tracker_042 : public ITracker
+class rift_tracker_042 : public QObject, public ITracker
 {
+    Q_OBJECT
+
 public:
     rift_tracker_042();
     virtual ~rift_tracker_042() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
 private:
     double old_yaw;
diff --git a/tracker-rift-080/ftnoir_tracker_rift_080.cpp b/tracker-rift-080/ftnoir_tracker_rift_080.cpp
index 00f3d5b3..4d351dbc 100644
--- a/tracker-rift-080/ftnoir_tracker_rift_080.cpp
+++ b/tracker-rift-080/ftnoir_tracker_rift_080.cpp
@@ -35,7 +35,7 @@ rift_tracker_080::~rift_tracker_080()
     ovr_Shutdown();
 }
 
-void rift_tracker_080::start_tracker(QFrame*)
+module_status rift_tracker_080::start_tracker(QFrame*)
 {
     ovrResult code;
     ovrGraphicsLuid luid = {{0}};
@@ -52,7 +52,7 @@ void rift_tracker_080::start_tracker(QFrame*)
                           ovrTrackingCap_Orientation | ovrTrackingCap_MagYawCorrection | ovrTrackingCap_Position,
                           ovrTrackingCap_Orientation);
 
-    return;
+    return status_ok();
 error:
     ovrErrorInfo err;
     err.Result = code;
@@ -63,11 +63,7 @@ error:
     if (strerror.size() == 0)
         strerror = "Unknown reason";
 
-    QMessageBox::warning(nullptr,
-                         "Error",
-                         QStringLiteral("Unable to start Rift tracker: %1").arg(strerror),
-                         QMessageBox::Ok,
-                         QMessageBox::NoButton);
+    return error(strerror);
 }
 
 void rift_tracker_080::data(double *data)
diff --git a/tracker-rift-080/ftnoir_tracker_rift_080.h b/tracker-rift-080/ftnoir_tracker_rift_080.h
index e5ad9c3a..e7fccb5e 100644
--- a/tracker-rift-080/ftnoir_tracker_rift_080.h
+++ b/tracker-rift-080/ftnoir_tracker_rift_080.h
@@ -25,7 +25,7 @@ class rift_tracker_080 : public ITracker
 public:
     rift_tracker_080();
     ~rift_tracker_080() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
 private:
     double old_yaw;
diff --git a/tracker-rift-140/rift-140.cpp b/tracker-rift-140/rift-140.cpp
index ebcc7654..9880cb1e 100644
--- a/tracker-rift-140/rift-140.cpp
+++ b/tracker-rift-140/rift-140.cpp
@@ -35,7 +35,7 @@ rift_tracker_140::~rift_tracker_140()
     }
 }
 
-void rift_tracker_140::start_tracker(QFrame*)
+module_status rift_tracker_140::start_tracker(QFrame*)
 {
     if (OVR_FAILURE(ovr_Initialize(nullptr)))
         goto error;
@@ -43,7 +43,7 @@ void rift_tracker_140::start_tracker(QFrame*)
     if(OVR_FAILURE(ovr_Create(&hmd, &luid)))
         goto error;
 
-    return;
+    return status_ok();
 error:
     hmd = nullptr;
 
@@ -56,11 +56,7 @@ error:
 
     ovr_Shutdown();
 
-    QMessageBox::warning(nullptr,
-                         "Error",
-                         QCoreApplication::translate("rift_tracker_140", "Unable to start Rift tracker: %1").arg(strerror),
-                         QMessageBox::Ok,
-                         QMessageBox::NoButton);
+    return error(strerror);
 }
 
 void rift_tracker_140::data(double *data)
diff --git a/tracker-rift-140/rift-140.hpp b/tracker-rift-140/rift-140.hpp
index 47eb7cd2..13bebed4 100644
--- a/tracker-rift-140/rift-140.hpp
+++ b/tracker-rift-140/rift-140.hpp
@@ -25,7 +25,7 @@ class rift_tracker_140 : public ITracker
 public:
     rift_tracker_140();
     ~rift_tracker_140() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
 private:
     double old_yaw;
diff --git a/tracker-rs/ftnoir_tracker_rs.cpp b/tracker-rs/ftnoir_tracker_rs.cpp
index 89659086..ebcdac33 100644
--- a/tracker-rs/ftnoir_tracker_rs.cpp
+++ b/tracker-rs/ftnoir_tracker_rs.cpp
@@ -44,7 +44,7 @@ void RSTracker::configurePreviewFrame()
     mImageWidget->show();
 }
 
-void RSTracker::start_tracker(QFrame* previewFrame)
+module_status RSTracker::start_tracker(QFrame* previewFrame)
 {
         qDebug() << "tracker_rs: starting tracker";
 
@@ -55,6 +55,8 @@ void RSTracker::start_tracker(QFrame* previewFrame)
     startPreview();
 
     mTrackerWorkerThread.start(QThread::HighPriority);
+
+    return status_ok();
 }
 
 void RSTracker::startPreview(){
diff --git a/tracker-rs/ftnoir_tracker_rs.h b/tracker-rs/ftnoir_tracker_rs.h
index 083794ed..bcf787a0 100644
--- a/tracker-rs/ftnoir_tracker_rs.h
+++ b/tracker-rs/ftnoir_tracker_rs.h
@@ -21,7 +21,7 @@ class RSTracker : public QObject, public ITracker
 public:
     RSTracker();
     ~RSTracker();
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
 
 public slots:
diff --git a/tracker-s2bot/ftnoir_tracker_s2bot.cpp b/tracker-s2bot/ftnoir_tracker_s2bot.cpp
index 6621e605..8bd1f5db 100644
--- a/tracker-s2bot/ftnoir_tracker_s2bot.cpp
+++ b/tracker-s2bot/ftnoir_tracker_s2bot.cpp
@@ -85,11 +85,13 @@ void tracker_s2bot::run() {
     timer.stop();
 }
 
-void tracker_s2bot::start_tracker(QFrame*)
+module_status tracker_s2bot::start_tracker(QFrame*)
 {
     start();
     timer.moveToThread(this);
     m_nam->moveToThread(this);
+
+    return status_ok();
 }
 
 void tracker_s2bot::data(double *data)
diff --git a/tracker-s2bot/ftnoir_tracker_s2bot.h b/tracker-s2bot/ftnoir_tracker_s2bot.h
index d4d3fd2a..f0493284 100644
--- a/tracker-s2bot/ftnoir_tracker_s2bot.h
+++ b/tracker-s2bot/ftnoir_tracker_s2bot.h
@@ -30,12 +30,12 @@ struct settings : opts {
     {}
 };
 
-class tracker_s2bot : public ITracker, private QThread
+class tracker_s2bot : public ITracker, private virtual QThread
 {
 public:
     tracker_s2bot();
     ~tracker_s2bot() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
 protected:
     void run() override;
diff --git a/tracker-steamvr/steamvr.cpp b/tracker-steamvr/steamvr.cpp
index d250197b..82a38fb7 100644
--- a/tracker-steamvr/steamvr.cpp
+++ b/tracker-steamvr/steamvr.cpp
@@ -183,16 +183,16 @@ steamvr::~steamvr()
 {
 }
 
-void steamvr::start_tracker(QFrame*)
+module_status steamvr::start_tracker(QFrame*)
 {
-    with_vr_lock([this](vr_t v, error_t e)
+    return with_vr_lock([this](vr_t v, error_t e)
     {
+        QString err;
+
         if (!v)
         {
-            QMessageBox::warning(nullptr,
-                                 tr("SteamVR init error"), device_list::strerror(e),
-                                 QMessageBox::Close, QMessageBox::NoButton);
-            return;
+            err = device_list::strerror(e);
+            return error(err);
         }
 
         const QString serial = s.device_serial().toString();
@@ -201,13 +201,7 @@ void steamvr::start_tracker(QFrame*)
         const int sz = specs.count();
 
         if (sz == 0)
-        {
-            QMessageBox::warning(nullptr,
-                                 tr("SteamVR init error"),
-                                 tr("No HMD connected"),
-                                 QMessageBox::Close, QMessageBox::NoButton);
-            return;
-        }
+            err = tr("No HMD connected");
 
         device_index = -1;
 
@@ -220,13 +214,13 @@ void steamvr::start_tracker(QFrame*)
             }
         }
 
-        if (device_index == -1)
-        {
-            QMessageBox::warning(nullptr,
-                                 tr("SteamVR init error"),
-                                 tr("Can't find device with that serial"),
-                                 QMessageBox::Close, QMessageBox::NoButton);
-        }
+        if (device_index == -1 && err.isEmpty())
+            err = tr("Can't find device with that serial");
+
+        if (err.isEmpty())
+            return status_ok();
+        else
+            return error(err);
     });
 }
 
diff --git a/tracker-steamvr/steamvr.hpp b/tracker-steamvr/steamvr.hpp
index 0592dec9..c8712b20 100644
--- a/tracker-steamvr/steamvr.hpp
+++ b/tracker-steamvr/steamvr.hpp
@@ -76,7 +76,7 @@ class steamvr : public QObject, public ITracker
 public:
     steamvr();
     ~steamvr() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
     bool center() override;
 
diff --git a/tracker-test/test.cpp b/tracker-test/test.cpp
index c662051e..d37d7373 100644
--- a/tracker-test/test.cpp
+++ b/tracker-test/test.cpp
@@ -30,9 +30,11 @@ test_tracker::~test_tracker()
 {
 }
 
-void test_tracker::start_tracker(QFrame*)
+module_status test_tracker::start_tracker(QFrame*)
 {
     t.start();
+
+    return status_ok();
 }
 
 #ifdef EMIT_NAN
diff --git a/tracker-test/test.h b/tracker-test/test.h
index 01133617..1b432be2 100644
--- a/tracker-test/test.h
+++ b/tracker-test/test.h
@@ -10,7 +10,7 @@ class test_tracker : public ITracker
 public:
     test_tracker();
     ~test_tracker() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
 
 private:
diff --git a/tracker-tobii-eyex/tobii-eyex.cpp b/tracker-tobii-eyex/tobii-eyex.cpp
index e35c849e..604931d6 100644
--- a/tracker-tobii-eyex/tobii-eyex.cpp
+++ b/tracker-tobii-eyex/tobii-eyex.cpp
@@ -217,10 +217,8 @@ void tobii_eyex_tracker::event_handler(TX_CONSTHANDLE async_data_handle, TX_USER
     txReleaseObject(&event_handle);
 }
 
-void tobii_eyex_tracker::start_tracker(QFrame*)
+module_status tobii_eyex_tracker::start_tracker(QFrame*)
 {
-    dbg_verbose("start tracker");
-
     bool status = true;
 
     status &= txInitializeEyeX(TX_EYEXCOMPONENTOVERRIDEFLAG_NONE, nullptr, nullptr, nullptr, nullptr) == TX_RESULT_OK;
@@ -231,9 +229,9 @@ void tobii_eyex_tracker::start_tracker(QFrame*)
     status &= txEnableConnection(dev_ctx) == TX_RESULT_OK;
 
     if (!status)
-        dbg_verbose("connection can't be established. device missing?");
+        return error(QCoreApplication::translate("tobii", "Connection can't be established. device missing?"));
     else
-        dbg_verbose("api initialized");
+        return status_ok();
 }
 
 tobii_eyex_tracker::num tobii_eyex_tracker::gain(num x)
diff --git a/tracker-tobii-eyex/tobii-eyex.hpp b/tracker-tobii-eyex/tobii-eyex.hpp
index a86a4a76..8583acf0 100644
--- a/tracker-tobii-eyex/tobii-eyex.hpp
+++ b/tracker-tobii-eyex/tobii-eyex.hpp
@@ -28,7 +28,7 @@ class tobii_eyex_tracker : public ITracker
 public:
     tobii_eyex_tracker();
     ~tobii_eyex_tracker() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
     bool center() override
     {
diff --git a/tracker-udp/ftnoir_tracker_udp.cpp b/tracker-udp/ftnoir_tracker_udp.cpp
index b3df5e60..41aa96c2 100644
--- a/tracker-udp/ftnoir_tracker_udp.cpp
+++ b/tracker-udp/ftnoir_tracker_udp.cpp
@@ -29,9 +29,6 @@ void udp::run()
     QByteArray datagram;
     datagram.resize(sizeof(last_recv_pose));
 
-    if (!sock.bind(QHostAddress::Any, quint16(s.port), QUdpSocket::ShareAddress | QUdpSocket::ReuseAddressHint))
-        return;
-
     while (!isInterruptionRequested())
     {
         if (sock.hasPendingDatagrams())
@@ -69,10 +66,15 @@ void udp::run()
     }
 }
 
-void udp::start_tracker(QFrame*)
+module_status udp::start_tracker(QFrame*)
 {
-    start();
+    if (!sock.bind(QHostAddress::Any, quint16(s.port), QUdpSocket::ShareAddress | QUdpSocket::ReuseAddressHint))
+        return error(tr("Can't bind socket -- %1").arg(sock.errorString()));
+
     sock.moveToThread(this);
+    start();
+
+    return status_ok();
 }
 
 void udp::data(double *data)
diff --git a/tracker-udp/ftnoir_tracker_udp.h b/tracker-udp/ftnoir_tracker_udp.h
index 0167a005..8e8a385c 100644
--- a/tracker-udp/ftnoir_tracker_udp.h
+++ b/tracker-udp/ftnoir_tracker_udp.h
@@ -19,12 +19,12 @@ struct settings : opts {
     {}
 };
 
-class udp : public ITracker, protected QThread
+class udp : protected QThread, public ITracker
 {
 public:
     udp();
     ~udp() override;
-    void start_tracker(QFrame *) override;
+    module_status start_tracker(QFrame *) override;
     void data(double *data) override;
 protected:
     void run() override;