Check out this page: http://answers.ea.com/t5/The-Sims-3/FAQ-Save-Errors-Error-12-13-15-16/td-p/652
It may not list your exact error, but these are very helpful. especially:
As soon as you get the error, the save is written to a folder with the extension .bad. You'll find it in your saves folder. Delete that folder before continuing. << so check your save folder under my documents/electronic arts/sims3 and make sure you delete any file that has .bad after it.
Use save as and a new name instead of save
Never use save & quit. Always save your game first and then quit the game without saving.
Check the folder under my documents/electronic arts/sims3CurrentGame.sims3 before starting the game. It should be empty. It only contains data during gameplay. If your game crashed, this folder might still contain something. Move or delete it's content.
I have used these a lot and have a lot less problems. Please check out the posts at the begining of the forum for some very helpful information.
