Missing all original maps and playlist (error)

I have gotten a big problem with my Halo Reach. All the maps and matchmaking playlists are gone. The only thing I can see is the Halo Anniversary map pack. That I have not even bought. I contacted Xbox support but they had never heard that kind of error. So after a while they asked me to look in the forums. I hope there is any other that have had this problem.

Try deleting Halo: Reach and/or Halo: Anniversary from your hard drive if you have them installed.

Also, have you tried going back to the main menu then to the Matchmaking lobby when this occurs?

this is happining to me to
i don’t understand is see only anniversary matchmaking:(

Whenever this happens to me my game is still loading all the playlists, and then all the playlists come up when i hit B then try to choose the playlist again. So your game is probably still loading up.