LOL Client Won't Update

Whenever I try to launch the client, I'm prompted to restart the client because there are "critical updates" to install, but when I click on it, it just restarts the client and shows the same prompt. I've tried starting up the client with adblock turned off, and have reinstalled the client 3 times, and it hasn't fixed anything. I play on Mac, and this began right after the Sett update.