MIDI Monitor Broken in MacOS Big Sur

Question

MIDI Monitor Broken in MacOS Big Sur

Closed this issue 4 years ago · 5 comments

This error message pops up when opening the application, MIDI Destinations then disappears as expected after receiving this error. I did reinstall and it didn't make a difference, however even once past the error message no MIDI Sources are receiving any data.

Answer 1 · 2020-08-25T04:52:48.000Z

Thanks for letting me know. Not sure what's going wrong, probably some new security thing, but I'll have to fix it.

I should give up on trying to have the app install its MIDI driver when it starts up, and instead just provide an installer package. That would require a restart, but the whole process might be more reliable.

Answer 2 · 2020-09-19T04:20:36.000Z

Which version of Big Sur were you using?

As of Big Sur beta 6 and 7, I'm not seeing this alert.

What I am seeing is that the "spy on output to destinations" feature doesn't work. That looks like a bug on Apple's side. I filed an issue in Feedback Assistant: FB8712999.

Answer 3 · 2020-11-01T07:35:54.000Z

Never mind; I can repro the original problem now on Big Sur 11.0.1 Beta (20B5012d). Fixed in commit 48dec8d.

("Spy on output to destinations" still doesn't work, and that's still Apple's bug.)

Answer 4 · 2020-11-12T21:50:22.000Z

This should now be fixed in version 1.4.1.

Answer 5 · 2023-03-05T20:54:46.000Z

to add to this, for anyone who's trying to get spying to work on an older version of macOS:

MIDI Monitor may install its driver into the user library folder, i.e. ~/Library/Audio/MIDI Plugins, while other drivers are available in e.g. /Library/Audio/...
in addition, the driver may remain quarantined. the quarantine flag may be removed using xattr -d -r ...
moving the non-quarantined driver into the common midi drivers folder appears to fix things after a restart.(/Library/Audio/... for older macOS, e.g. Mojave etc; and ~/Library/Audio/... on newer macOS)