If troubleshooting cannot solve your problem, please don't hesitate to report an issue.

1. I can't hear anything!

  1. Check current audio driver in the option dialog. Do not use an audio driver that is not installed on your system.
  2. If you are using an external device, make sure your audio equipments are correctly set up.
  3. If no soundfont is loaded, the internal synthesizer won't make any sound...
  4. Check audio driver/buffer settings in the synth section.
  5. Check if your midi file is valid/has correct bank selecting method/has zero volume.

2. The playback is intermittent.

Try increasing audio buffer size and/or audio buffer count in synth options.

3. MIDI timing is messed up.

This is a known issue under Windows. Try decreasing audio buffer size and increasing audio buffer count. Also make sure you are not using shitty cabling if you are using external synthesizers.

Also also, if you overload your computer (fluidsynth) or synthesizer too much, don't expect the timing would still keep up!

4. Some files cannot be played.

5. Some soundfonts cannot be loaded.

Files names with characters unsupported by the system locale won't load correctly in Windows. This is a known issue.

6. Sound is distorted.

Try reducing the master volume.

7. Bank selecting is incorrect for the internal synth.

Change default midi mapping if necessary.

8. Bank selecting is incorrect for external devices.

Bank selecting messages are sent to external devices directly. The midi file may be incompatible with your device.

9. 3D visualization is upsidedown/rotated/black/blinking.

If you are experiencing rotated and blinking visualization, try setting Visualization-Video/Multisampling to 1 or above. If that doesn't solve your problem or you see nothing at all, please send me more details about your problem (graphics card, drivers etc.).

Devices/drivers reported to have this issue:

10. External devices connected but does not show up.

Always connect your device before launching QMidiPlayer and make sure it is not used by another application. If it still refuses to work, make sure your device is working within some other MIDI applications. If it doesn't, try reinstalling the driver, checking the cables ... even turning it off and on again?

If it works in programs other than QMidiPlayer however, you're probably facing a new bug in QMidiPlayer.

11. Tweaking the values in channel editor does nothing.

It depends. Sound modules from different vendors accept different sets of controller messages. As for fluidsynth, it relies on the modulation matrix of the soundfont. Sadly most of the soundfonts floating around on the Internet do not have modulation matrix declared.

12. I've got an issue not mentioned above. How do I report it?

Please use the GitHub issue tracker. When you're reporting an issue, please provide the following details about your issue:

If the issue is about a crash, providing a relevant back trace will help tremendously. For Windows users, you may run QMidiPlayer in console with the --keep-console argument, try to reproduce the crash, and take all output in the console, which may look like this: 

C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64>qmidiplayer.exe --keep-console
Loaded plugin: C:/Users/chrisoft/Software/qmidiplayer-0.8.7-dev-x86_64-w64/plugins/libmidifmt-plugin.dll
Loaded plugin: C:/Users/chrisoft/Software/qmidiplayer-0.8.7-dev-x86_64-w64/plugins/libsampleplugin.dll
Hello world from plugin init!
Loaded plugin: C:/Users/chrisoft/Software/qmidiplayer-0.8.7-dev-x86_64-w64/plugins/libvisualization.dll
Unhandled exception occured at 0x0041df59: access violation.
The data at memory address 0x000001d8 could not be read.
0x0041df59 in _ZN13qmpMainWindow13funcReflectorENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE at /home/chrisoft/builder/QMidiPlayer/qmidiplayer-desktop/qmpmainwindow.cpp:695 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\qmidiplayer.exe
0x0046e0b1 in _ZN9QtPrivate11FunctorCallINS_11IndexesListIJLi0EEEENS_4ListIJNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEEEvM13qmpMainWindowFvS9_EE4callESD_PSB_PPv at /home/chrisoft/builder/QMidiPlayer/build/qmidiplayer-desktop/../../../mxe/usr/x86_64-w64-mingw32.shared/qt5/include/QtCore/qobjectdefs_impl.h:152 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\qmidiplayer.exe
0x66953b40 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Core.dll in ZN11QMetaObject8activateEP7QObjectiiPPv (No symbols)
0x004018f7 in _ZN21QReflectivePushButton7onClickENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE at /home/chrisoft/builder/QMidiPlayer/build/qmidiplayer-desktop/qmidiplayer_autogen/EWIEGA46WW/moc_qmpmainwindow.cpp:316 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\qmidiplayer.exe
0x0046e4af in _ZNKSt12_Mem_fn_baseIM21QReflectivePushButtonFvNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEELb1EEclIJRS6_EvEEvPS0_DpOT_ at /home/chrisoft/builder/mxe/usr/lib/gcc/x86_64-w64-mingw32.shared/5.5.0/include/c++/functional:600 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\qmidiplayer.exe
0x66953b40 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Core.dll in ZN11QMetaObject8activateEP7QObjectiiPPv (No symbols)
0x024e5f81 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN15QAbstractButton7toggledEb (No symbols)
0x024e7c2d from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN15QAbstractButton13keyPressEventEP9QKeyEvent (No symbols)
0x024e7d85 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN15QAbstractButton17mouseReleaseEventEP11QMouseEvent (No symbols)
0x02445368 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN7QWidget5eventEP6QEvent (No symbols)
0x02407adc from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent (No symbols)
0x0240f543 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN12QApplication6notifyEP7QObjectP6QEvent (No symbols)
0x66928bca from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Core.dll in ZN16QCoreApplication20sendSpontaneousEventEP7QObjectP6QEvent (No symbols)
0x0240ddba from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN19QApplicationPrivate14sendMouseEventEP7QWidgetP11QMouseEventS1_S1_PS1_R8QPointerIS0_Ebb (No symbols)
0x0245b335 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN14QDesktopWidget11qt_metacallEN11QMetaObject4CallEiPPv (No symbols)
0x0245e0c0 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN14QDesktopWidget11qt_metacallEN11QMetaObject4CallEiPPv (No symbols)
0x02407adc from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent (No symbols)
0x0240e9e3 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Widgets.dll in ZN12QApplication6notifyEP7QObjectP6QEvent (No symbols)
0x66928bca from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Core.dll in ZN16QCoreApplication20sendSpontaneousEventEP7QObjectP6QEvent (No symbols)
0x01ebea5e from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Gui.dll in ZN22QGuiApplicationPrivate17processMouseEventEPN29QWindowSystemInterfacePrivate10MouseEventE (No symbols)
0x01ebfec5 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Gui.dll in ZN22QGuiApplicationPrivate24processWindowSystemEventEPN29QWindowSystemInterfacePrivate17WindowSystemEventE (No symbols)
0x01ea10de from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Gui.dll in ZN22QWindowSystemInterface22sendWindowSystemEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (No symbols)
0x66981db6 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Core.dll in ZN28QEventDispatcherWin32Private14sendTimerEventEi (No symbols)
0x6b75e108 from [unknown module] in CallWindowProcW (No symbols)
0x6b75db49 from [unknown module] in DispatchMessageW (No symbols)
0x6698110a from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Core.dll in ZN21QEventDispatcherWin3213processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (No symbols)
0x6dd362e5 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\platforms\qwindows.dll in qt_plugin_instance (No symbols)
0x66926bb4 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Core.dll in ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (No symbols)
0x669303ce from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\Qt5Core.dll in ZN16QCoreApplication4execEv (No symbols)
0x00476f30 in main at /home/chrisoft/builder/QMidiPlayer/qmidiplayer-desktop/main.cpp:71 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\qmidiplayer.exe
0x004013bd in __tmainCRTStartup at /home/chrisoft/builder/mxe/tmp-gcc-x86_64-w64-mingw32.shared/gcc-5.5.0.build_.crt/../gcc-5.5.0.build_/mingw-w64-v6.0.0/mingw-w64-crt/crt/crtexe.c:341 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\qmidiplayer.exe
0x004014fb in mainCRTStartup at /home/chrisoft/builder/mxe/tmp-gcc-x86_64-w64-mingw32.shared/gcc-5.5.0.build_.crt/../gcc-5.5.0.build_/mingw-w64-v6.0.0/mingw-w64-crt/crt/crtexe.c:225 from C:\Users\chrisoft\Software\qmidiplayer-0.8.7-dev-x86_64-w64\qmidiplayer.exe
0x69bf6fd4 from [unknown module] in BaseThreadInitThunk (No symbols)
0x6b97cf31 from [unknown module] in RtlUserThreadStart (No symbols)
Append that to your issue report (make sure it doesn't contain any personal data first). For Linux users, you usually already have a coredump for the crash. Please refer to the documentation of your distribution for how to take a back trace from that coredump.