I used to have Spotify but now it says it is damaged or incomplete, and now I can't open it again. How do I fix that?
There's official manual about it:
Reinstalling gives the app a new lease of life; fixing many common issues you may be experiencing.
Note: Any offline playlists will need to be re-synced once reinstalled.
- Click Spotify in the menu bar then Quit Spotify.
- Open Finder then click Go > Library in the menu bar. (You may need to
hold the Alt key if Library isn’t visible).
- Open Caches and delete the com.spotify.Client folder.
- Click the back arrow.
- Open Application Support and delete the Spotify folder.
- Download and install Spotify!