If you do not find a match after a few minutes, please restart your search. I'll keep you updated below as the situation unfolds.
We've encountered a problem and couldn't join you to the game. If you have been banned by Industries, you'll see a message when you launch Halo 5: Guardians indicating that there is an enforcement in place.
Your fireteam is too large for the selected activity. Overall loading time is improved, and this is getting closer to expected matchmaking behavior. REQ Cards are unavailable to be used during Warzone.
REQ Packs can't be purchased from the store or in-game.
If you encounter this error while playing with friends in the same region, restart the game and try again. Halo: MCC has been out in the United States for 18 hours now, and tonight will be the first full evening that most customers who've purchased the game have time to sit down and enjoy it.
Close and restart the game to trigger an update you'll need to be connected to Xbox Live to download any available updates.
Step 3: Check your console connection See Network settings on Xbox One for help troubleshooting connection problems between your console and the online network services. This means that a mandatory update is available for the game, and the latest version is required for you to continue.
The update deployed to matchmaking was done on the server side and does not require an extra download to your Xbox One. The official Xbox Live status still states that the service is "Limited.