I just installed Yosemite about 2-3 days ago on my 15" MacBook Pro and everything was working great up until now. All of a sudden my wifi just cut out and everything just froze. I couldn't open any applications up and if they were open they would not close. The spinning beach ball will not go away and I can't click on anything. I've been hard shutting down and rebooting to see if it would solve the issue but it doesn't. Sometimes I get stuck at the gray loading screen and sometimes I don't. Force quitting applications doesn't work either. Whenever I put it into safe mode it works fine though and everything is normal. Not sure if this is a Yosemite problem or my MacBook is just corrupt. Mavericks was working fine for me as well before I installed. Any thoughts?