I've recently gotten my friend Cod Waw and had him install some custom zombie maps off of ZombieModding and other sites without the UGX Map Manager or  The Official UGX Maps. I've personally had the UGX Map Manager for a while; when I played with him when I had it installed and he didn't, he was able to join my lobby and start the game with me. But once I had him install the Map Manager, and had him try to join my lobby for the first time after that installation, he was unable to join and kept getting the Session No Longer Available Error however many times he tried. I've also had this happen with others in the past when they installed it and we all had pretty good connections. Would anyone happen to know a fix? (I'm sort of guessing re-installation of the Map Manager might help if anything else won't work.)