Board Thread:Bug Reports/@comment-19737107-20141221090138/@comment-25370207-20141224020749

Can't be the connection, it says shut down. As far as I know, shutdowns are caused by updates(dunno if this still happens though) and bans, like ROBLOX bans. Regular player-admin bans can(I think) disconnect or crash you.

But for only one player to shut down, it's client-sided so it's something in your PC. Or, yeah, having CE running in the background.