Please take a look here: http://answers.ea.com/t5/The-Sims-3/FAQ-Save-Errors-Error-12-13-15-16/td-p/652
These are things which can help you:
- Use save as and a new name instead of save
- Try saving in Edit Town mode as well as live mode
- Try saving your game paused and unpaused and at different speed levels.
- Move your saves folder to the desktop
- Never use save & quit. Always save your game first and then quit the game without saving.
- Don't use spaces or special chars in your save game names.
- If you have lots of stuff in your inventory, reduce it.
- If all fails, quit your game without saving and restore a backup.
