So I just finished installing Halo and was getting reading to play some online but when I started up the game I got a message saying there was an error authorizing user with Halo 5 Guardians services, is anyone else having this problem? Is there a way to fix it?
If it helps I was on the last level when it crapped out on me. Won’t let me back into the game.
I’m experiencing the same error as well. “Error authorizing user with Halo 5: Guardians services. You will unable to access online modes”
I was playing the campaign and multiplayer perfectly last night at launch. Not sure what’s going on here.

Having the same issue
oh great, happening to everyone
Well 343 manage to ruin another halo game
Try checking support section
This just happened to me just now. Waited about 2 hours for the game to install after I got home from work at about 12.15 am, then was able to play online until about 4 am perfectly. I woke up today and got ready for work, was gonna play a few matches before I headed out and then I got this same error you speak of.
I just hope the issue is resolved when I get back home from work tonight or this is really going to blow. So far I haven’t seen anyone find a solution for this.
Funny mine says " unable to connect to the Halo 5 : Guardians Lobby Service "
Can this issue be fixed please 343 ? I’d like to play this game on my day off 
Yeah I tried resetting my xbox, cable modem and checked the xbox services. Everything is up. Its for sure a 343i server issue. Lets hope its not a DDOS.
Great; just about to leave work. Hope this is resolved by the time a park myself on the couch. Tried to play last night but by 12 I had too many whiskeys!
I’m having a high packet loss problem, when I check multiplayer network conection it shows I have packet loss 93%, which I’m not able to play any online mode, such co-op, Arena, or any online custom games…
I tried hard reset, re-install the game, even formatting my xbox, but still the problem isn’t solved…
please 343 help