[CRASH] Changing runes in champ select causes client to crash

When I am in champ select, I sometimes crash. I think it happens when I want to change my runes page. I am never able to change them properly. When i modify them and want to save these change,I click the save button multiple times but it never saves. When I click the exit button, it says something like : Do you want to save the changes. But, I have already ¨saved¨ them or tried to. This bug makes my lol client crash. Moreover, it makes me unable to change rune page between game. It doesn't happen every game