I am having a problem similar to this - for the last 3-4 days. I will be playing a file, it will freeze completely (not just lag) and either crash to the desktop, or if I check task manager, it will say that sims 3 is not responding and I have to force quit the application.
In the last few days, I've tried the following solutions, and have still had the problem:
Factory reset
Complete uninstall and reinstall (I have base game, WA, Ambitions, Generations and a few store items - riverview, baby swing)
My current game file had this happen numerous times before I attempted these fixes, and crashed again this morning after, so I decided to test run a new file. I started a new game in Riverview, playing Jon Lesson. Got to breakfast of sim day 2 and it crashed.
I did have mods running - overwatch, error trap, story progression and master controller - and the latest thing I did was remove those.
I only upgraded to the latest patch when I reinstalled everything last night, so the problem happened both before and after the latest patch.
FWIW - my system exceeds basic requirements: dual 2.4 GHz processors and 6G ram.
I'm not sure what else to try at this point - it is getting frustrating.