Game closes in loding screen

Hey, Im a EUW player and i always keep suffering from this bug (some friends of mine too), losing lp and getting 20mins leaver buster from it. after a while in loading screen, my game closes by itself, telling me to check my internet connection and i click on reconnect .. my team had remade already, it happened to me yest, and today 2 times ... 3 times in a row. and when i did get rid of the first 20min leaver buster .. the next game this happens and i get the 20mins penalty again. I hope i made this issue clear enough and i'm waiting for a responce. Thank You.