Black screen during champion select
A black screen occurred during champion select for me. It was a first which disabled me from banning or playing. I don't have a screenshot sadly as I wanted to quickly force-quit my client and reload it so I could get back the screen to its proper form.
The entire client was entirely black except for the top-right buttons: _ ? o x [Basically, the exit button, settings.. The ones right above the friends list].
