Crashing during champion selection

Hello. Almost in every game, during champion selection it crashes and this a message apears saying "A problem has been encountered and the program needs to close" and then "send error report" , "don't send". It happens almost in every single game. I don't know what to do. Then it opens again and because I couldn't choose a champion I have a time ban. But I don't care so much about the time but I care about the fact I loose LP. It just happened again and I lost 10 LP.