VCV Rack Crash selecting midi device

Opening on Windows 10, it starts with a “demo patch” up, select Windows Midi, select midi device name, crash. Log has this segfault in it

[26.653 fatal src/main.cpp:45] Fatal signal 22. Stack trace: 26: ZN4rack10appDestroyEv 0x456435 25: raise 0x733cabe0 24: abort 0x733cf1e0 23: ZN9__gnu_cxx27__verbose_terminate_handlerEv 0x6fc5f170 22: ZN10__cxxabiv111__terminateEPFvvE 0x6fc581b0 21: ZSt9terminatev 0x6fd302b0 20: _cxa_throw 0x6fd39080 19: ZN7MidiApi5errorEN11RtMidiError4TypeENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE 0x733d52 18: ZN11MidiInWinMM8openPortEjRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE 0x7366e2 17: ZN4rack12RtMidiDriver14subscribeInputEiPNS_4midi5InputE 0x74b050 16: ZN4rack4midi5Input11setDeviceIdEi 0x48080c 15: ZN4rack2ui8MenuItem8doActionEv 0x4a49ae 14: ZN4rack5event5State12handleButtonENS_4math3VecEiii 0x4576c8 13: ZN4rack7updater17isUpdateAvailableEv 0x45914e 12: glfwPlatformUnlockMutex 0x4d78ae 11: CallWindowProcW 0x73c1e460 10: CallWindowProcW 0x73c1e460 9: glPushClientAttrib 0x47ce9e80 8: CallWindowProcW 0x73c1e460 7: DispatchMessageW 0x73c1e040 6: glfwPlatformPollEvents 0x4daf66 5: ZN4rack6Window3runEv 0x4594ea 4: main 0x781840 3: main 0x781840 2: main 0x781840 1: BaseThreadInitThunk 0x73b07020 0: RtlUserThreadStart 0x73f22630

Does the MIDI device have a funky name? Like with special characters or some such in it?

Most likely the device is occupied by another application and cannot be opened by Rack.

Ahh yeah, Windows, I forget :slight_smile:

I said this before but there is so much false information flying around on this topic:
This not a Windows issue or limitation. Microsoft‘s default MIDI drivers don’t support multiple applications simultaneously but it depends on the device driver. Windows does support multi-app for one device but the vendor needs to support it by the device driver.
Rack crashing in this situation is a topic on its own and should be considered a bug. More robust error handling would fix that.

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I have a flaky MIDI foot controller that was crashing rack every time I selected it. Unplugged it and stuck it in a different USB port, suddenly it stopped crashing. Made no sense at all because a Beatstep worked perfectly on the same connector…