How to Overcome Error Code 12

If you play The Sims 3, like I do, you might have come across Error Code 12 when saving your game. Just so you know, this has nothing to do with the state of your actual save game file, it actually has something to do with the world file your save game is based on! Actually, it has nothing to do with that either, more so, it has something to do with the copy of the world file that is stored within your save game file (which is actually a folder, but the game sees it as a file), which might have been corrupted or deleted or something which makes it unreadable by the game (renaming, deletion, corruption, etc.).

By now you may be thinking "Oh great so my save game is permanently damaged", guess what, YOU'RE WRONG! The Sims 3 is so smart that when it loads the save game, it loads EVERY SINGLE FILE inside of the save game folder, so not all hope is lost, however, we have to manually trigger the restore mechanism, and I'll show you how to do that now.

Steps 1 - 6

1. Switch out of the game (DO NOT CLOSE IT, just switch windows using Alt + Tab on a PC, or Command + ~ on a Mac)

2. Open a Windows Explorer or Finder window (essentially just go to your Documents folder).

3. Browse to where save games are, well, saved (If you don't know where these are look at the bottom of this post).

4. Delete any folder that has a name ending in .bad AND has your save game's name at the beginning of it (e.g. Michael's Game.sims3.bad). These are the failed saves.

5. Cut the folders that have your game's name at the beginning and end with .sims3 or .backup (e.g. Sariah's Game.sims3 or Sariah's Game.sims3.backup) and paste them into a backup folder (maybe create a folder to paste them in called "Sims 3 save backups" on your desktop) (these are the active save games that the game loads and their backups)
* If no backup exists, I found that just deleting the .bad file, returning to the game and saving will fix the problem.

6. Try saving again (don't worry about lost files, the game will automatically generate new ones, which may cause the save process to take longer than usual as more data is being copied from RAM into permanent storage)

So that should get you back on your feet! I hope this helped!

Peace everyone!

SAVE FILE LOCATIONS:

Windows Vista and 7:

C:\Users\USERNAME\Documents\Electronic Arts\The Sims 3\Saves
Windows XP: C:\Documents and Settings\USERNAME\My Documents\Electronic Arts\The Sims 3\Saves

Mac:

Macintosh HD\Users\USERNAME\Documents\Electronic Arts\The Sims 3\Saves

How to fix "Error Code 12" in the Sims 3 (PC & Mac)
by: katiecatsims

[secretvamp]

Hello in 2026. This didn't work for me (although I still think it's got valuable info, it's always good to delete those .bad files and have backup saves). What DID work for me was disabling memories in Options. I had apparently put the setting on disable notifications, so I guess they were piling up in the background.

Edit: So it worked for about 5 minutes lol. What DID finally solve the issue was the following:
- NRAAS Master Controller to reset the town and Total Annihilation on homeless non-service sims, strays and wild horses
- NRAAS Overwatch for unroutable Sims/broken vehicles
- Turning off story progression to avoid more animals populating spontaneously
- Removing all family inventory items (also check personal inventory and bookshelves)
- Save As instead of Save (ALWAYS)
- Deleting cache files and TravelDB

Hope this helps future players

[KimmieBuns]

If I may add something- this error also comes up if you don't have enough RAM/storage space.

[Algester]

the true way to overcome code 12 is infact not "invasively" using Build and Buy and Create a Style as this is where crux of most memory issues (RAM/game cache) of the game happens the secondary issue is that its ASKING SO MUCH for a 32 bit game as its meant to run on ALMOST ALL POTATO PC hardware

[YOU DON'T NEED TO KNOW MY NAME]

It also did not worked for me as well , the game still gave error code 12

[AncientGatekeeper]

OOOF. Sorry to hear you lost 1hr30m.

[TurbowFett]

Hmm this didn't work for me.

I had to reload a previous save. Luckily I have Nraas saver. had to go back 2 saves which was 1 hour and 30 minutes lost but that's okay because I'm something like 120-200 hours into this town.

The only thing I can think of that caused it was adding a stair case to a 2nd level basement that, for whatever reason, the game removed. I'm on a custom world so, I'm 99% sure that's what caused it.

[KendraDaBlob]

Thank you so much, when this glitch happened I almost died. I'm playing a legacy and even though I'm on gen 1, like, this family has gone the second farthest any family I have ever had. So in conclusion you saved me from dying internally. :)

[AncientGatekeeper]

Glad my guide is still working after all these years!

[horrorscopes]

you are a lifesaver, favorited and awarded. thanks! :))

[banditka]

This post has been SO helpful!! I play Sims 3 on PC (not on Steam) and it work perfectly! Using it again for the second time, thank you so much!!