I am having a similar problem. I have entered my Priority Alpha code and finished the Spartan, Wetwork, Operator, and Tracker specializations. After capping those specializations I returned to select my next and they were all gone. Correct me if I am wrong, but I thought the code was for ALL of the new specializations... If so, where did they go? I tried redownloading the file and restarting the game and still no luck. This is a last resort. Hoping actually posting on 343's forums will produce a solution as it is 343's game I'm having a problem with.