Mac dies when opening League [Crash]

I had this problem of where when I tried to open League, it would crash and my whole screen would have stripes all over it. I went to go get it checked later on and turns out it was because the hard drive was dead. I got it replaced back in December and it was fine until now. I open League or at least try to see what happens when I open it (usually when this problem comes up it gets to the login screen and dies). My whole computer screen is all covered with stripes and I don't know if its a League problem. I just replaced my hard drive not long ago.