[Client]When i accept a game, the client crush and i can't pick any champ

When i accept a game, the client crush and i can't pick any champ, so the next time i try to do a game (any tipe so custom, ranked or normal) i have to wait some minutes that increases every time this thing happends, and it happends every time so i couldnt play a game for a a long time. Now i'm still having this problem, since the last patch, 5.7