@Missyann33 I've moved your post to the Sims 3 PC tech section. Just so you know, the game has been out of development for six years now, and in all likelihood, there are no patches or other fixes forthcoming.
Try removing everything in family inventory that you can and only then selling the other items. If that doesn't work, leave the movable items out, save, quit, and delete the five cache files in your Sims 3 game folder in Documents. They should be deleted regularly anyway, and every time you quit the game while troubleshooting. For reference, they are:
If this doesn't help, go to Edit Town, evict your sims, and immediately put them back in their house. They'll keep their jobs and relationships but lose their promised wishes and opportunities. Use "save as" to rename the save, so you have your original save as a backup. Then quit (without saving, as a separate step—this is always best practice), delete the cache files again, reload, and test.
There are other ways to try to unstick the items, like moving your sims to a new lot, either through Edit Town or by using the in-game function. Let me know if nothing works.
