Client crashing in the champion select

It happens randomly sometimes my League of Legends Launcher crashes in the champion select (Ranked/Draft and Blind pick) .. and so i have the 6 minutes penality AND the LP penality if it is a ranked game + i had a leaver buster right now and it resets the timer like i didn't wait the damn 20 minutes .. What i'm i supposed to do ? Will riot fix this or do i have to do something ? Does someone else have this issue ? Thank you.