Error 12

Error 12 is an out of resources error. Usually it is RAM so running your ongoing game with an eye on the Task Manager was exactly the right thing to do. But it could also be an overload on video memory (vram) or what the game calls "virtual memory." There are some other things we can do reduce stress on the game even if the RAM usage never appears to be leaping into the danger zone.

-- Make sure that your system still has plenty of RAM left to allocate. If other processes not related to the game are running away with 5 or 6 GB of it, the game isn't going to get enough to use. Multiple browser processes (esp Chrome, but now also Firefox) can do this.

-- Check your frame rates in-game with the fps on cheat code. Runaway frame rates usually lead to outright glitching and crashes, not Error 12s, but such wouldn't be unheard of. The fps rate should never exceed the refresh rate of your monitor. Most are 60 Hz, so 60 fps, some can run higher. TS3 does not have a built-in fps limiter. Even if you already arranged for this, check to make sure it's still staying capped.
-- May sound silly, but make sure the game is actually using your Nvidia graphics card (am assuming you are playing on the one with the new card in the 1050 range your posted about prior). Arranging the fps capping typically takes care of this at the same time.

-- Save (as), quit all the way to the desktop (or Origin if on Patch 1.69) more often. The longer a game session runs in realtime hours, the more resources it will keep trying to call for that it never really puts back. This can be especially true after CAS (and its subsets) and Edit Town are used extensively.

-- Have NRaas Overwatch, ErrorTrap, Register, Traffic (to prevent the overspawnage of performance limos and other vehicles that OW later has to clean up) in play.
-- Check on the size of your ongoing gave save, in particular the nhd file of the homeworld being played. Is it huge, as in over 500 MB? If so, there are save cleaning techniques that can be used on it.

-- Play offline, that is, not logged in at the Launcher level or in-game, and forego the online features of the game.
-- Switch off the in-game EA TS3 store shopping experience from within Game Options.
-- Switch off the hidden object startup game, also from within Game Options (this starts the game out at a higher level of resource usage).
-- Switch off scrapbook memories or use a mod to control them.
-- Use MC to check on the total Resident population of the world. On City Hall or an in-game computer, NRaas > MC > Demographics > Population > "X" to dismiss the filter. Too high on the Residents number (the others don't usually matter as much unless they are in the thousands or something) can put things on overload especially if running NRaas StoryProgression.

Try my suggestion...

1.ALWAYS use save as instead of save or save and quit.
2.ALWAYS save as and quit the game every 2 hours. The longer you play , The more memory leak and the dreaded error 12.
3.If you get error 12 during save then try lowering these settings to minimum (resolution , edge smoothing , high detail lot). Chance you will save successfully is > 90% according to my test. If save successfully then turn those graphics back to your preferences and quit.
4.Try save game from edit town.
5.If the game always crash during save because of max memory used consider cutting back some custom contents. There is nothing you can do about this.

Thank you for your answer!

"igazor;c-16264184" wrote:
-- Make sure that your system still has plenty of RAM left to allocate. If other processes not related to the game are running away with 5 or 6 GB of it, the game isn't going to get enough to use. Multiple browser processes (esp Chrome, but now also Firefox) can do this.

I usually play with only Sims 3 and a screen capture program open, the latter pretty much not taking up anything. I used to play with Chrome open, but nowadays not anymore.

"igazor;c-16264184" wrote:
-- Check your frame rates in-game with the fps on cheat code. Runaway frame rates usually lead to outright glitching and crashes, not Error 12s, but such wouldn't be unheard of. The fps rate should never exceed the refresh rate of your monitor. Most are 60 Hz, so 60 fps, some can run higher. TS3 does not have a built-in fps limiter. Even if you already arranged for this, check to make sure it's still staying capped.
-- May sound silly, but make sure the game is actually using your Nvidia graphics card (am assuming you are playing on the one with the new card in the 1050 range your posted about prior). Arranging the fps capping typically takes care of this at the same time.

Oh I did hear about The Sims sometimes not using the graphics card it is supposed to use. I have no idea how to do this but I'll try looking into it.

"igazor;c-16264184" wrote:
-- Save (as), quit all the way to the desktop (or Origin if on Patch 1.69) more often. The longer a game session runs in realtime hours, the more resources it will keep trying to call for that it never really puts back. This can be especially true after CAS (and its subsets) and Edit Town are used extensively.

-- Have NRaas Overwatch, ErrorTrap, Register, Traffic (to prevent the overspawnage of performance limos and other vehicles that OW later has to clean up) in play.
-- Check on the size of your ongoing gave save, in particular the nhd file of the homeworld being played. Is it huge, as in over 500 MB? If so, there are save cleaning techniques that can be used on it.

-- Play offline, that is, not logged in at the Launcher level or in-game, and forego the online features of the game.
-- Switch off the in-game EA TS3 store shopping experience from within Game Options.
-- Switch off the hidden object startup game, also from within Game Options (this starts the game out at a higher level of resource usage).
-- Switch off scrapbook memories or use a mod to control them.
-- Use MC to check on the total Resident population of the world. On City Hall or an in-game computer, NRaas > MC > Demographics > Population > "X" to dismiss the filter. Too high on the Residents number (the others don't usually matter as much unless they are in the thousands or something) can put things on overload especially if running NRaas StoryProgression.

With the exception of NRaas Register and Traffic, I did all of this either yesterday or as soon as I got the computer. Just to make sure the Memories wouldn't slow down everything I used MC to delete all Memories from every Resident in the Town.
Regarding the population, I need to check how many there are around, I think I accidentally removed the limit for how many sims there could be, but I'm not too sure.
And as for the .nhd file in my save folder, it's around 150 MB.

In case this is needed, here is a graphic on how to set up the Nvidia Control Panel for vertical sync and to cap the fps.
http://forums.thesims.com/en_US/discussion/comment/15007970#Comment_15007970

Note that this method only works in full screen mode. If the fps does not stay locked in, as can be seen by using the fps on cheat code in-game, or if windowed mode is required, then we move on to Nvidia Inspector or other tools such as RivaTuner Stats Server (RTSS).

Back on the RAM usage, it can be surprising how much in the way of resources Chrome might be "using" even if you don't have any browser windows or tabs open. Always worth checking on that in Task Manager as well; in particular, how much of that 8 GB is actually available for use while the game is still running at 2.something or 3 GB. But if you have plenty to work with still, then of course we can rule that out.

"igazor;c-16265238" wrote:
In case this is needed, here is a graphic on how to set up the Nvidia Control Panel for vertical sync and to cap the fps.
http://forums.thesims.com/en_US/discussion/comment/15007970#Comment_15007970

Note that this method only works in full screen mode. If the fps does not stay locked in, as can be seen by using the fps on cheat code in-game, or if windowed mode is required, then we move on to Nvidia Inspector or other tools such as RivaTuner Stats Server (RTSS).

Back on the RAM usage, it can be surprising how much in the way of resources Chrome might be "using" even if you don't have any browser windows or tabs open. Always worth checking on that in Task Manager as well; in particular, how much of that 8 GB is actually available for use while the game is still running at 2.something or 3 GB. But if you have plenty to work with still, then of course we can rule that out.

Okay, I'll try fixing it now. I usually play in windowed mode because my sims 3 game seems really dark otherwise, for some reason. I'll edit the post if it works.
Edit: I got Register and Traffic in the meanwhile as well and checked the population (199 sims).
Edit 2: FPS goes from 60 to 9.

Error 12 is a big pain in the rear end to deal with. I've beat my head against the computer several times in this thread:

http://forums.thesims.com/en_US/discussion/915571/the-latest-on-error-12/p1

If you're playing in a custom world with a lot of store add-ons or custom content, or you're using custom lots, that can add to the resources used that the game needs. That turned out to be my problem, as I have a lot of lots I have downloaded that I like to use in my games. All those bars, registers, special items, etc, add up.