@chris This is the first time it's happened to me as far as i can remember, usually just naming and structuring the files and folders is enough for plex to correct itself. iTunes also had issues, for some reason it recognised volume 1, 3 and 4 of this collection and their respective disc fine but decided volume 2 should be split between volume 1 and 3 which carried over to plex even though it had vol 2 in it's database.