The Sims 3 has been prone to a lot of crashes since the Ambitions expansion pack.
A couple of things you could try is disabling Data Execution Prevention for The Sims 3 and all expansions (add all the .exe files to the excluded list). And try The Sims 3 crash fix from here
. These two fixed crashing problems in TS3 for me.
You could also try re-installing every game, but don't install the patches yourself. Install each game and expansion in order, but let the expansions update the game themselves. I think EA recommended this themselves as a fix for some problems when installing Ambitions as it was conflicting with some previous patches.