[Client] Black screen with no working buttons.

Upon trying to get on League this morning I noticed that for some reason my client simply does not work. The screen is black and the launch button isn't even there. I tried clicking on the settings and whatnot to see if I could troubleshoot, but that doesn't work either. I've tried restarting my computer, restarting my modem, changing/disabling firewall, and running as administrator. The last time I played League was yesterday, and there was no issue.