[SOLUTION] Black champion select screen
The problem with this patch is your friends list.
A recent change in the patches is friends list. Now, whenever you start a game, you can still view your friends list. Before, you couldn't.
So, everytime you start the game/champion select, it has to load your whole friends list.
Solution?
Hide your friends list before starting the game/ queueing up. IT worked for me.
A second kinda of solution is removing all your friends (!Not recommended!) I removed mine from 310-->197 and it helped a few seconds.
If both don't work, you'll have to wait until RIOT fixes it :S
tl;dr : Close friends list (or remove them)
NOTE: Always check if your friends list is closed, mine re-opens each game.
Good Luck, hope this helps! [slayer-jinx-catface]