Error (-3201) when saving Music Library on Mac

Try holding down option as you launch Music to explicitly select your library in case it is inexplicably linked to a cached version of the database that doesn't get updated correctly.

Try holding down option+cmd as you launch Music to open it in its safe mode. They may help fix internal errors in the library.

Did you look for .tmp files inside the Music Library.musiclibrary package?

tt2

Apologies, I know I covered some steps you're already tried, but did you try my first step? After doing that it may be worth trying the second step again, which is why I left it in.

If you have Time Machine set up and covering the Music folder you might try restoring a copy of the .musiclibrary package from a date before this issue cropped up.

tt2

macerror -3201

Mac OS error -3201 (kENOENTErr): No such file or directory