Can't move...

Alright, I'm putting this up for my friend but he for some reason can't move with his mouse. Everything around him is working just find no lag, and if he changes his move click to like a letter on the keyboard it works but he can't move with right click... It won't let him move at all. He has around 100 fps on very high settings and 30 ping. I've tried everything to see if it works for him but he can't move. The game isnt really fun to move with a button on the keyboard. Please help. He's on MAC btw.