My Spotify app won't open, can't be deleted and won't force quit on macOS ...and yet when I try to, a dialogue box tells me I can't delete it because it's already open.

Any ideas what I can do?
Make sure Spotify isn't in your login items (System Preferences → Users &amp; Groups) so it won't automatically start. Log out, making sure to uncheck ‘Reopen windows when logging back in’, then log back in. Try to delete the app now.