Go to Electronic Arts > The Sims 3
Delete the cache files.
Go to your Saved Sims folders and delete the savedsims.index (not sure that's the name, but it will be the only index file)
In the Download folder, sometimes some .bin files will pop up, you can delete those too
Then there's the DCBackup folder, it's a package save of all the sims3pack things you installed via launcher, delete all but the ccmerged file.
And you can delete all the images in the FeaturedItems folder.
If none of that helps, maybe it's a cc quirk.
Hope it works tho, good luck!