league error during middle of game

in the middle of my game every single game at about the 30 minute mark, i get a message saying error, it freezes my computer and i have to restart my computer and re connect back into the game and its very frustrating because it gives me leaver buster for 10 minutes for 5 games and then 20 minutes for the next 5 games, this is very frustrating and i need help asap please.