Why is my League of Legends not opening after pressing the launch button in the launcher?

So basically I'm addicted to League because it's such a fun game but now it won't open. So what happens is that when i open the launcher, I would press the orange launch button then league just disappears and i can't play anymore . I was wondering if anyone knows how to solve this. It would mean so much if someone can tell me how to fix this. Thanks for reading this. :)