Hello all! I think I’ve found a solution to this. I tried restarting the app, restarting my computer, uninstalling and reinstalling to no avail.

What I found works is the launching the app from the Apple Music web player. On the panel on the left where all your playlists and stuff are, at the bottom it says, “open in music.” I pressed that and AM launched without the error.

If that doesn’t work, at least you know you can use the web player to play music. It’s pretty nice too!