I just tried to play Halo 5 on my Xbox on my main account (Mentok) and it came up saying there was a profile sync error and to check my connection. I hard reset my console, deleted my account from my Xbox and then added my account, but still get the same error. I can play other games just fine.
Also, every time I want to visit my online profile on Halo Waypoint [My Profile, Service Record or even Settings] it says “Problem Detected - Well, this is embarrassing. Looks like we have some problems on our end.” Even when I wanted to post this problem with the account it says “You have reached your daily limit of 0 forum posts.” I had to create a new outlook email and xbox live account just so I could post here about this problem.