MuseScore 4 first time startup problems
I tried to start the new MuseScore 4 (v 4.0.0) and it would die with no errors.
The log file would end with:
2022-12-21T07:15:11.171 | WARN | main_thread | MidiInputOutputController | checkConnection: failed connect to device, deviceID: 0:55:8, err: failed open port, error: UNKNOWN
I finally found a folder called "vst" near the log folders. I cleared out the JSON files and started up Musescore. One or two JSON files were added and MuseScore died. Hmm...
So I ran it again and it added a few more. Well, I have a number of VSTs, so it took a while, but after it located all my VSTs and created JSON files for them, it finally started.
Clearly, whatever is creating the JSON files is causing a timeout error in the MIDI I/O controller. This should be fixed, but the workaround is to just keep starting MuseScore 4 over and over.