If you have multiple versions of the same movie or TV episode, let’s say you have two versions. Then you delete one version and scan the library. When you try to play the movie of TV episode the player will get stuck in the spinning wheel and nothing will happen. My client is the Apple TV, not sure about other clients.
The solution is either to enter and choose the other version in the player GUI (you have to guess because you do not know which one is the available one) and then it will work. Or go to the server and Empty Trash for that library and everything will work again.
The GUI should not receive all the versions of the movie, it should receive only the available ones. Or at least it should default to an existing one.
This is annoying because if you use Radarr/Sonarr they might first download a version of the Movie/Episode and then if they find a better one according to your configuration they will download the new version and replace it. Sonarr and Radarr can refresh the database but they can’t empty trash, so this creates the need of manual intervention. Automatic emptying trash after every refresh is not an option for me (too dangerous if one drive is not available).