Greetings.
I have a certain issue, you see I have completed Halo Reach on solo legendary soon after the release of halo reach and I also played campaign afterwards then and their; however, today when I went to play some campaign it loaded the level “nightfall” and said I have yet to start it 
All previous mission were also only completed in heroic.
I think nightfall was the last campaign level I played before it went all haywire, but that was a very long time ago, I mostly likely played it for a challenge.
I positive that I, nor has anyone else been messing with the memory of the Xbox, so I not sure what has happened.
I have enlisted in the Xbox live beta, but I not sure if that affects anything, nor should that effect my campaign progress in halo reach.
I don’t have the time to complete the game again in solo legendary. So I was wonder if this problem is temporary (which I highly doubt), or what.
Solutions please?
(sorry for the grammar and spelling )