UPDATE: Came back this evening, seems to be working fine. Not sure what the cause of the error was. Advice would still be appreciated.
Premium US user Macbook Air early 2015 Sierra 10.12.3
I quit Spotify earlier in the day. I opened it again and the song I was playing was paused on the menu bar and I tried to navigate to a different song not in my library by looking up the artist. I could click on the song I wanted but nothing happened and the menu bar did not change.
I tried playing a song downloaded to my library, and it let me play the audio but did not change the play bar's album icon or pause button. I then tried to play a different song but it wouldn't let me play the second song at all, just kept playing the first song. I could not pause the song through the play bar or through the option by right-clicking the icon in the dock. The only way to stop the music was to quit the app. Each time I tried to quit the app, however, it closed the window but would not quit. When I right-clicked on it in the dock, it said it wasn't responding and I had to force-quit it. It did this every time I tried to quit it after troubleshooting. In short, the app let me play one song from my library but just played the audio, and I could not pause it or play a new song from the interface.
Things I have tried:
Clearing the cache in .com.spotify.client
Removing the Spotify folder in Application Support and reinstalling (now the spotify folder has disappeared even though a new version has been installed) I tried reinstalling multiple times, deleting all the files related to spotify I could find.
I restarted my computer.
I was using Bluetooth headphones when it froze, so I turned off the connection, quit and reopened the app.
None of these steps have fixed the problem. I can't play music while this error is occuring, and I'm not sure what I should do next.