You can only Plex Dance files which are still in existence.
You can not perform a Plex Dance on files which have already been removed from a library.
Instead of a Plex Dance, you can simply remove the whole library section and let it rebuild.
But before doing that, I urge you to confirm that there is no damage in your database file. The above instructions about server logs were intended to do that.
If you continue to work witrh a damaged database, it could cause complete data loss down the road.
