Well, I don't know about you, but I just tried getting on to LoL and it won't let me access the log-in screen. What happened earlier was that after it got done updating, it wouldn't take me to the log-in screen, but soon after my anti-virus system (AVG, if you're curious) said a threat had appeared and I recognized it as to maybe be a RADS error of a different kind because I saw RADS in the threat name. So, I click remove, then it asks me to restart to complete removing the threat, I say yes, then it takes a while, then it doesn't restart my laptop and instead says it had to do a system shutdown because the restart failed. So, now, after that, I've clicked LoL about three times, brought to the launcher, clicked Launch, and then nothing happens.
I suspect that when that restart error occurred or when the threat was first being removed, something might have been deleted in my LoL files and is now preventing me from playing LoL. So I don't know if I should uninstall it, then reinstall. As of now, I just tried doing what Eambo suggested and I'm still getting the same error. :/