I have a problem with the multiplayer i want launch a game offline with bot but the loading lock after the middle of loading ( before i never has this problem. I played a lot of game alone with bot.)

i want join an online server in bo2 zombie or Mp but in the end of loading i have error.

Error you have been disconnected from the Call of Duty Black Ops Ii servers.
I can play only in solo games and the loading is long why ?