i'm getting an error message that says "a serious error has occurred while loading [save file name]. it is strongly recommended that you restart the application" when my sims try to travel home from vacation - is there a way to fix this or do i just have to go back to the save from before the vacation?

Before reverting to an older save, try traveling to and from a vacation world in a new save. Sometimes this error results from a system issue and not anything about a particular save.

If traveling in the new save works, try using MasterController to reset the vacation world before traveling. It can also help to empty out your sims' inventories, and of course to quit and reload immediately before starting the travel transition itself.

Before reloading, be sure to delete the cache files in Documents\Electronic Arts\The Sims 3 as well:

• CASPartCache.package
• compositorCache.package
• scriptCache.package
• simCompositorCache.package
• socialCache.package

The source of the "serious error" is often (but not always) attributable to having the TS3 user game folder files open and "in use" at the time the game needs to load them. Just having them open in Windows Explorer can sometimes be enough to trigger it.

I also saw this error after deleting my World Cache files. I wasn't able to open my recent saves for one of the worlds until I restored the World Cache files from the recycle bin. That hasn't happened since, and I often clear those world caches, so I don't know why it happened that time.

Did you by any chance clear the World Cache for the homeworld?

tried travelling on another save, which worked fine so it seems it's a problem with this save specifically. unfortunately deleting the sims 3 cache files + mastercontroller reset everything don't help!
i don't have any game files open and haven't deleted the world cache as far as i'm aware.

(never mind.)

does this mean the home world is corrupted?

It's possible this save is somehow corrupted, but you don't need to give up on it yet if you don't want to. Try traveling again, except this time, do all of the following:

• Empty your sims' inventories as much as possible. A few items is fine; a hundred is not.
• Immediately before you want to travel, use "save as" to rename the save, then exit 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 user folder in Documents: CASPartCache, compositorCache, scriptCache, simCompositorCache, and socialCache. Empty out everything in FeaturedItems as well.
• If you play through Origin, sign in and then put Origin in offline mode. Now disconnect your computer from the internet—turn off wifi and/or pull the ethernet cord.
• Launch the game, load the save, and travel your sims right away, as soon as the game clock starts moving forward.