"LOLClient.exe has stopped working" Help please

Okay so when i am ingame the game runs very smoth without any problems whatsoever. But when i am in the lobby/shop/searching games (i dont have any problems after a match has been found). The big problem is that most of the times if it takes more than 30 sec to find a match it crashes and i get 5 m bans etc. BUt since i gotta wait more bcuz of the bans it crashes more. this is a major issue for me since i love this game and it makes me unable to play at some points. It mostly crashes right when i am supposed to "accept" or "deny".

I tried reinstalling the whole game + launcher and it still doesnt work. i've also tried diffrent settings at properties. i have had the game run in windows 7,8,10 but its the same however i do.

I have Windows 10 on my pc, and as said before its no prob ingame of after i accept a match.

Any suggestions? help needed :D