mrsawright33 Try recovering a backup copy of this save. Even if you never created a backup, the game saves the data from the second-to-last time you saved your progress. Open Documents > Electronic Arts > The Sims 3 > Saves, and you'll see a folder with your save name, plus another folder with the same name and a .backup extension, for example SunsetValley.sims3 and SunsetValley.sims3.backup.
Rename the save and delete the .backup extension (e.g. SunsetValley1.sims3), and that version of the save should be available to load at the Main Menu.
Please also delete the five cache files in this same Sims 3 folder. They should be deleted regularly anyway, and while troubleshooting, every time you quit the game. For reference, they are:
- CASPartCache.package
- compositorCache.package
- scriptCache.package
- simCompositorCache.package
- socialCache.package
Even if the backup save has the same outline of a house rather than the proper preview, you can still try loading it. The missing preview has multiple causes, not all of which are indications of corruption.