I've never had this happen in my game. If you play with any kind of mods or custom content, regardless if it comes from the Sims3Store, Exchange or 3rd Party CC, you may want to try to play without them.
Move the mods folder to your desktop. Opening the launcher, click the Installed Content Tab. Checkmark Run Game Without Custom Content. Then click the Play button.
A few other tips to try:
Try Resetting the whole town, in Edit Town mode - Press Shift-Ctrl-C keys together to bring up cheat console and then type in resetsim *
(resetsim FirstName LastName to reset individual Sims)
Try playing your current family(s) in a new game. -- This is different than moving them into a different house or moving them to a different town. Save the household(s) and place them into a new game to see if things run smoother from there.
If these fail, try a Factory reset - Copy your Sims 3 folder to the desktop. Rename your
current Sims 3 folder to something like Sims 3 Current. Click the Sims 3 icon to create a new Sims 3 folder. Then copy your game saves, files and such over to the new game to see if that helps. (This is different from a total-game reinstall)
How To: Saving folders/files to use on a different computer or to use as backup
http://www.carls-sims-3-guide.com/forum/index.php/topic,16414.msg313134.html#msg313134If none of the above help, please post back so we can try to troubleshoot some more.
MrsFlynn