After game black screened. Long loading time

After I finish the game I sit and wait roughly 2-3 minutes before the screen loads and allows me to honor a teammate. After that I wait even longer with often a black screen. It is frustrating because often times I'm in a party and get I get kicked because I'm stuck in black screen hell.

I have completely wiped my computer. I have uninstalled league and reinstalled it.

Can I get some insight or help to correct this? I rather enjoy league and would like to play it in a more fluid manner after the game.

Pls help.