Missing purchased TV shows

My entire season 6 of futurama that I purchased on apple TV is no longer showing up my library. Its the season with the 4 movies, but now when I go to my library I just have seasons 1-5 and 7-10. If I search for season 6 it shows up on apple store, but if I click on those episodes (movies) if make me go to Hulu which I do not have subscription. I paid for these a long time ago, how can they just remove them???