[CLIENT] Unclickable client during post-match Overview

Immediately after winning a game the post-match Overview screen is darker and unclickable.

I just won my gold promos, so I was expecting the congratulations pop-up to appear, but it did not. It seems to be a visual bug where the dark overlay behind the congratulations pop-up appeared, but not the pop-up (therefore there is no button to close the overlay). The client is clearly NOT frozen, because I can still see the post-game chat and game invitations as they appear. However, I can't click on anything.

Another interesting thing is that the champion mastery bar is just spinning and seems to have failed to load.