Click Launch, Log-in Screen won't show up.

So I click the LoL Icon and the usual thing comes up and I click launch, and then nothing. It just wont open the log in screen. No error screen, no nothing, just doesn't open anything. I can open the league launcher as many times as I want but as soon as I click launch it disappears and nothing. I really don't want to reinstall league so wondering if anyone might have any solutions. Thanks!