[CLIENT] Black screen in team arrangement lobby

Since everyone seems to be getting the black screen in the champ select itself, I haven't found a solution to my problem, as I cannot even get that far. My black screen occurs in the "Arranging team" group lobby where you invite your friends (or not), so whether I start a group or get invited to one, I cannot see the players or pick my primary/secondary roles, thus preventing me from even making it to the Queue.

[EDIT] This only occurs in Draft Pick team arrangement, not blind pick