[Client] Black Screen on Champ Select, Forced to Dodge

A few minutes ago, I queued up for a ranked game, as one is wont to do. A game came up, I accepted, and my screen went black. All that was present was a loading screen saying "retrieving data from server". After closing that window, my client screen remained black with my cursor replaced by the loading icon. With nothing to do, I was forced to close the client, dodge, and lose 3lp. Apparently this is not a new problem, but I haven't had it before so far as I can recall.