https://bugs.winehq.org/show_bug.cgi?id=44974
--- Comment #1 from Sagawa sagawa.aki+winebugs@gmail.com --- Created attachment 61405 --> https://bugs.winehq.org/attachment.cgi?id=61405 proposed patch
Could you try this patch? This patch fixes the issue on my side.
MIDI stream routine now opens a MIDI Out device without callbacks. Otherwise, i.e. it opens a MIDI Out device with the same parameter for callbacks, a superfluous MOM_DONE message is sent when it uses midiOutLongMsg internally.