promblem

when i want to open a server or a personal game i get to the screen when i select the map and the server name and i press "done" it writes "loading..." on the screen and when you see the blue screen with orange letters down at the left its closing the game i dont know why can somebody help me...

Ok........ i need help whenever i go to play online i click on a server and it says you are running on a different protocal soemthing and i have version 2.0 what do i do?