Currently THETVDB id for Knightfall is set to 305851.
https://www.tvmaze.com/showexternal/view?id=11312
Correct THETVDB id is 323608.
https://www.thetvdb.com/?tab=series&id=323608
Hey,
I have corrected it, but could you please use our edit request thread next time for small edits like these? https://www.tvmaze.com/threads/2677/edit-requests
Thanks,