Good Morning 343 Industries to make this quick and brief I’ll get straight to my issue. I managed to beat Halo 4 Campaign on the Legendary difficulty, but was not given the two achievements for beating the campaign on legendary and for beating it on legendary solo titled " The Legend of 117" and " Lone Wolf Legend" I believe this is due to a bug that will reset your campaign progress back to the beginning at random but you are able to resume from where you left off creating a “gap” between the mission you are on and the prologue mission. I really don’t feel like re doing the campaign for a couple reasons one being it was hard enough the first time, two for fear of the campaign doing the glitch again has it has been multiple times.
Has well due to the Crimson DLC Matchmaking and Majestic DLC Matchmaking playlists being removed I have been unable to claim the achievements for them as well in regular matchmaking and although the ones I tried for, and should’ve earned are forgotten, I’m more than willing go for them again, but would like to know whether I’ll even be able to unlock them.
To end positively I’ve grown up with Halo since Halo CE, and was sad to see Bungie leave the franchise, but after Halo CE Anniversary and Halo 4 I can see it’s in good hands and that you’re doing a great job with the universe I have come to love (would love to see more weapons make it to the sandbox though like in previous versions as well as dual wielding miss those two aspects very much 
just saying lol.) Definitely excited for the next installment to the franchise and hope it makes even larger leaps than Halo 4 did (return of firefight alongside Spartan Ops perhaps) would appreciate a reply ASAP to this
Yours truly:
Devon Harris
XBOX LIVE Gamertag: CR4FTYGH0ST <---- not an o in ghost is a zero