Client froze, now fails to open

I had just left the Practice Tool, and everything was normal. I then went to start a ranked game, but after I selected "Ranked Flex" the client froze and I couldn't back out of creating the game. So I logged out and logged back in. It took the client longer than normal to finish the "Authenticating" step.

I tried to go into the Practice Tool again. After I dismissed the window saying I wouldn't get any IP or XP, the client stayed in the setup lobby and would not progress even after clicking Start and saying OK to the popup window again. I then clicked the X to cancel the game, but when I returned to the home screen the button in the top left still said "Lobby" and would take me back to the game I was trying to cancel. **The client was stuck in a loop where I could not start the Practice Tool game, but couldn't back out of it either. **

I then logged out again, but when I tried to launch the client again, it wouldn't start at all. No login/patching screen, and not even the pre-login-screen little League icon showed up. I went to Task Manager, and it said League was not active. The result was the same when I tried again. **So now I can't get into any part of the client. **