When I try to log into my account, it says something along the lines of "The server is busy. Please try again later." When I try once more, it immediately says something similar to "You cannot be logged in for an 'unknown reason.' Please submit a ticket at <support URL>." The loading screen says up for a bit until the cancel button comes back. If I try to log in more, it just copies these two log in failure windows in this pattern.
I checked around, and it seems as though I'm the only person who has this problem, so the server isn't busy. So that probably means I did something to my LoL to mess it up, but the only thing I could think of that is out of the usual from my usual routine was that I updated the PBE client. I do keep my PBE LoL and actual LoL clients in different folders, though. PBE works just fine.