I got on today and none of my servers would load. I restarted the game about 3 or 4 times and then only 5 servers loaded, I tried to join one of those servers and my loading would keep getting stuck on "Validating serial number..." then it would pop up with "Unable to connect to the server"
Fixes I have tried already: Restarting Steam, Restarting M&B, Restarting PC, Unplugging Ethernet and plugging it back in.