Had new update and two computers wont work now

Did the new update and now game wont work. I dont even have any firewalls or anything active. Not sure what’s going on here. It goes thru the steps of loading into the game. Connecting. Retrieving realm list. Logging in to game server. Then I get hit with the same message. An error has occurred. Please try again later. BLZ51903021. Anyone have this problem before?