So I have been playing this game when possible since the launch date. I got my codes fine and everything and have leveled all the way to level 100. I have seen all 8 of the specializations available before. I am however now stuck at level 100 with it just saying SR 100 - SPECIALIZATION COMPLETE. When I go to specializations it just shows all 6 that I have complete including: Spartan-IV, Wetwork, Operator, Pioneer, Engineer, Rogue. I bought the season pass thing and have downloaded the crimson map pack and everything. I have downloaded and re-downloaded it all and still nothing. Someone please help! =(
Hmmmm… I wish I could… I haven’t seen that problem yet with mine and am only level 56. But no worries! There will definitely be someone on here who can help! 
Simply go to Xbox Dashboard and then re enter the game, its just a issue where DLC sometimes doesnt appear, happens now and then.
Before you bust a blood vessel.
> Have you tried clearing the Xbox’s cache and then re-downloading everything?
Going to the Dashboard or just turning the Xbox off and then back on and entering the game works, its just some sort of a glitch in my opinion, I have seen it eh 3 times so far I believe.
First.
Dashboard > Account Settings > Download History
Specialization Priority Alpha > Download again.
If that doesn’t work reset the cache and redownload everything. Sorry 343 makes terrible decisions. ( Yes that is an objective observation)