Please help game will start a match but it just says you are disconnected

So it will let me start a game but when it goes to play the game it goes black and says you are disconnected form the internet and it keeps telling me to try again. So i have to do the check for corruption and it will eventually let me play but its happened almost every time i open league to start a new game. So i have to continually leave games and its going to mess with my mmr. any ideas how to fix