Sims 3 crashes all the time on new MacBook Pro, what do I do?

Got a brand new MacBook Pro 13inch (not retina) for Christmas. I was advised when buying the Mac to update the ram if I wanted to use it for playing the Sims 3 (which I did). Previsoulsy I had a Sony VAIO (top spec) in which the Sims 3 worked on for years, however the past few months it started to crash saying "unexspected error". I thought at the time it was just my laptop starting to give in, as I had it for 6 years and was used everyday.

However I have just installed all my Sims 3 discs to my Mac and the exact thing is happening. Im not very tech when it comes to these things, all I can guess is maybe one of the games is corrupt? Or there is something wrong with the disc? I have purchased a new exspansion pack which should be here tomorrow to see if the problem is with the disc I am using now.

Any help would be appreciated, as one of the main reasons I bought my new Mac was because I thought the Sims 3 would work on it efficantley.

Many Thanks,

Rebecca