I completed the level Truth and Reconciliation and when I started The Silent Cartographer I backed out to the main menu. When I went back to the mission select menu I couldn’t select to play The Silent Cartographer… But I could select Assault on the Control Room despite having not gotten that far into the campaign.
Has anyone else had this issue?
Not I… but tbh, I didn’t stop to take a breath anyway. I just banged out the 1st half of the game in one sitting anyway… & I loved every moment of it 
hmm am not sure, at least if you played co op
I had that in the original Halo CE. I kept losing Silent Cartographer, then if I got it back I would lose the Library. I think it fixed itself after I played straight through the game again.
Awesome. So I just beat the game on Legendary and I didn’;t get the achievements for it. I still can’t see the silent Cartographer on the mission select screen and it doesn’t show that I ever beat Truth and Reconciliation.
Pretty disappointing.
I am having this problem. It only effects Co-Op but none of my progress is getting saved!
Lots of other people are having problems with this as well. Here are some posts about it: http://halo.xbox.com/Forums/yaf_postst46509_Bugs.aspx
http://halo.xbox.com/Forums/yaf_postst44356_Campaign-Difficulty-not-saving.aspx
http://halo.xbox.com/Forums/yaf_postst43770_Serious-saving-issues-with-cea.aspx
https://halo.xbox.com/Forums/yaf_postst43272_No-progress-saved.aspx
Ive had the same issue but it didn’t affect me getting all the missions done.