Fix for black-screen in champ select; Riot approved

So I actually sent a support ticket about the problem. The friend's list minimization wasn't working for me; I got advised by a Rioter to download their hextech repair tool and do a clean install.

Downloading the repair tool took awhile, but the clean install took only a minute or so. Haven't had problems since. Spread the word! Hopefully this will help people! Fixed it for me!