So I got a message from Xbox Live saying “I have earned a promotional REQ pack including the Teishen Raikou armor set” and went to redeem the code, but as soon as Halo 5 was done updating and I go to open it, I see I have no REQ packs to open. I quit the game and re-opened it but still nothing. I tried re-entering the code but it told me I had already used it.
… So what do I do?
Same here. Entered code got same message.
Same here! Also game is now crashing when trying to play campaign! What have they done? Its MCC all over again.
Promo pack is now working yay. The game is still crashing on campaign and is unplayable booooo.
This is a very late update but I hope everyone got the issues fixed, as it has been almost 2 months now. I was able to obtain my REQ pack after quitting the Halo 5 game via dashboard and resetting my Xbox to be sure… But I like to believe that I just have a guardian angel over at 343 Industries looking after me 
NOTE: For all who don’t know, holding down the power button on your Xbox One until it shuts down, that’s how you reset it.