Game wont let me get back in.

Before the game starts after champ select you normally go to the loading screen but for some instance the loading screen wont load and you get an error. It would say that unable to connect to server due to internet connection. Tried to go to other online games and surely they work fine and turned off antivirus. So I've tried 2 computers and three different internet connections and somehow once in a while this error pops up. You constantly retry to get in game but it wont let you. So in the end you just get penalized for not participating in game or being AFK. Anyone else have this issue?