CALL OF DUTY CONNECTION FAILED - Unable to access online services. FIXED w/ PHONE! MODERN WARFARE
Unable to access online services. I have found two fixes to this problem and have seen multiple complaints on the internet about it.
1. Make sure your SYSTEM is updated. Not the game, but the actual system.
2. WARZONE requires a STRONG internet connection. Use your cell phone HotSpot and it will work perfectly. When you test your internet on the system, it may say it is "all good" but it doesn't tell you how strong the connection is.