This is the second time I've run into this issue. Tried to delete an artist's scrobbles from my library, except it won't let me delete one scrobble, which it says doesn't exist. But the artist is still in my library somehow.
Joining in here. It says that I haven't scrobbled my top track yet... Please help us out, dear support team!
Edit: Did a little research; in another thread a bypass is suggested. Go to your overall scrobble list and delete wichever track you want directly from there... takes some scouring but it worked for me in the end. If you're using a PC, press ctrl+F to find the song faster.