Why does my Mac Apple Music library fail to load after quitting the app?

Quit the app (on Mac), when I opened it back up my library wouldn’t load (error 9039). The sync button had turned itself off eve though it was turned on when the app was last open. It was also saying I had exceeded the 100,000 song limit, which is not true. I tried signing out, now when I sign in nothing happens, it just ignores me.

[Re-Titled by Moderator]