Sims 3 Island Paradise Crash

hey, 

HELP.
I have Sims 3 Pets, Generations, Late Nights, Ambitions, Supernatural, Seasons, Showtime and Island Paradise. I applied the Manual Patch, Ultimate Fixes and Store Fixes so  I thought I was good on those. The game loaded fine, I ignored the Modification Error sign and I thought it would all be great from there. Having created my sim without any issues, I placed her on a lot in 'Isla Paradiso' and my sim froze and the game shut down. I was thinking maybe it was just all the custom content that sim is wearing, so I restarted the game and chose a household that was already moved in; that crashed too. I don't know what the problem is so I'm scared to try to fix it... 

I'm still a little unsure about what 'Custom Content' is or whether or not it will change my game. I downloaded sims and worlds from the Official Sims 3 website under The Exchange tab. Would that mess with my game ? It never has before... I deleted the worlds that I downloaded but I'm a little sad about deleting the sims. They came with cool outfits and lots of accessories as well as awesome hair styles.