My Friend has a server I have been playing for quite a while and it was working fine, but we decided to take some mods out. When I go on the server it works, but only when I jump or sometimes when I walk it immediately puts me back to the main screen after a few seconds and tells me "A fatal error has occurred this connection has been terminated." And we both don't know why. I have tried jumping and walking (etc.) in singleplayer and it works, so we don't know what the problem could be. Please if you could reply Asap that would be the best. Thank You.