Reply to Macbook crashes while using Traktor Pro!

I was using traktor pro a week ago (4decks) and suddenly traktor freezed! Since then it has happened several times and i don't know how to solve it. I have tought about upgrading the RAM but i don't know if that would solve the problem. If you could please help me i would be very happy!

Here are the spec's of my MBP:



p.s. most of the time when it happens i'm using TP with 4 decks