Deleted household after returning from university (64 bit and metal)

@alfonspalfons  There are a couple different approaches, depending on whether you use mods or are willing to try.  The non-mod-related approach involves lowering the stress on the game engine as much as possible during the travel transition and hoping it works out:

• Empty your sims' inventories as much as possible.  A few items is fine; a hundred is not.
• Use "save as" to rename the save, then quit (without saving) immediately before you want to travel.
• Load the game just to the Main Menu.  Turn off memories, the in-game shopping experience, and the hidden object interactive loading screens.
• Lower all the graphics settings to the minimum.  (You can revert to your normal settings after the travel transition.)  Now quit the game again, without loading a save.
• Delete the five cache files in your game folder in Documents: CASPartCache, compositorCache, scriptCache, simCompositorCache, and socialCache.
• Empty out everything in FeaturedItems as well.
• Sign into Origin and then put it in offline mode.  Disconnect your computer from the internet—turn off wifi and/or pull the ethernet cord.
• Now launch your game, load the save, and send your sim home right away, as soon as the game clock starts moving forward.

If everything is fine when you get back, you can "save as" and quit again, change your settings back to whatever you want, and go on playing.

Thank you so much!

I went ahead and copied my family and created a new game save. But next time it happens I'll definitely try this! 🙂 

Edit: The workaround posted by caprice812 on this thread seems to make it so that I can continue to play my game. However, random aspects of my sim have been reset. For example, none of the skills that I learned at University are still there, as well as my rank within social groups. I also think my University progress reset (I had been almost finished, but needed to come back home between terms). Some, but not all, of my collections and inventory have also reset. I think a bunch of the states are actually just the same as when I left for university, and it didn't save any of my progress except for my relationships. :-(

@puzzlezaddict Unfortunately, I seem to be having the same problem. I get the error message 

“some objects could not be loaded and were replaced” when returning from university, and my household is gone (where pictures of/info about my sim should be, I just see blank spaces). I tried the steps that you listed here, and still had the error. I also tried installing the nraas mods you had suggested on a different thread (errortrap, overwatch, and traveler), and they have also had no effect. I have no other mods installed, and no custom content (although, I do have some objects downloaded form the Sims3 store, none of which have been used in this save). 

@karategal49314  If you still have a save from University and are comfortable sharing it, I'd love to take a look at it.  Most of the people with this issue have been able to resolve it sooner or later, but I'm curious as to why it occasionally doesn't work.  Even if you don't make backup saves on your own, the game automatically keeps the backup from the second-to-last time you saved, so if you've only saved once since your sim returned form University, the backup would be from while they were there.

I think the reason the workaround helped but didn't preserve your sim's progress is that the game is loading the version of the homeworld your sim left but not your progressed sim.  So you're basically loading a save from before your sim went to University.  As to why the progressed version of your sim doesn't get placed back in the homeworld, I don't know.  Did you change the sim's outfits, hair, or some other details?  Did you add a sim to the household?  It's possible the game can't reconcile the two versions of the sim and errors out.  But that's just my speculation.