Did your PC come with Windows 11 natively? Mine is an upgrade from Windows 10, so I don't know if that makes a difference.

I also use the Steam version as well. My current Sims 3 playthrough has gone on quite long being at more than 5 generations. I also use a bit of custom content.

This would rule out custom content or large saves as causing the error given that your installation is a fresh on. I have had Error 16 one time in the recent past, however, but it was due to a community lot I downloaded, which may have been glitched or was incompatible with version 1.67.

I wonder if this 22H2 issue pertaining to The Sims 3 could have something to do with the Smart App Control (SAC) feature. Again, my issue was opening up save games (getting the "A serious error has occurred..." message upon loading), but this could also apply to saving.
This page is a guide on the feature. There are some directions showing how to get to the settings where there is an option to turn it off. This is something you could try. Note that if you want to turn it back on, then you have to do a full reset of your pc.
https://petri.com/windows-11-smart-app-control/
I didn't get a chance to try turning it off myself since I rolled back to 21H2 before I read about the SAC feature.

Also, are you having issues with any other DirectX 9 games with this version of Windows 11?

My install was a clean Win11 21H2 Win11 install, and I upgraded from that to 22H2 so I don't have the smart app control feature. My PC came with Win 10 Home, I am currently running Win 11 22H2 Education.

Anyway I did some further tests and gathered some interesting results.

First of all, I switched to Origin version just to confirm if this also happened on that version, and it does.

In my previous test, I only used the nointro package as a mod, which I didn't really consider important enough and as such I said clean user folder. However in my later tests, I also removed that and results were really interesting:

Also to clarify, all the tests below also include 4GB of Store content directly downloaded from EA and installed. All tests were done with a new game started on Isla Paradiso. I clicked Save immediately after the game loaded, did nothing in the map, or the game, saved with the default suggested name "Isla Paradiso". After each test, I removed Isla Paradiso saves, and bad save files. Edit: Isla Paradiso is EA's default Isla Paradiso, without any patches by EllaCharmed.

Test1:
-No Mods folder at all.
-The game saves successfully.

Test2:
-Mods folder with just nointromaxis.package.
-Error 16

Test3:
-Mods folder with nothing in it but the "Overrides" and "Packages" as directories, and the "Resource.cfg" file.
-Error 16

So, from my tests, even having the Mods folder with literally no mod in it causes Error 16. At this point I am really confused.

Edit: To clarify, I also had Smooth Patch installed while running the game, but only the Bin part, I didn't use any *.package files in the Mods folder. I also did all of these tests except Test1 once (I tested Test1 twice), so it is entirely possible I just got randomly lucky or something.

rsanda,
Along with the Windows 11 2H22 update, there was a cumulative update for .NET Framework 3.5, 4.8 and 4.8.1. Did you download and install that as well?

Another thing you may want to try is putting The Sims 3 program in the DEP (Data Execution Prevention) exception list. I had to do that a while back since it would occasionally crash to desktop (without an error message) due to DEP. I think already having the program in that exception list might have been a factor in me not getting the Error 16 on 2H22.

To get to the DEP settings on Windows 11:

1) Go to the Start tab on the taskbar at the bottom. Right click it and select Settings.
2) In the search box in the Settings window, type in "advanced system." Below that, "View advanced system settings" should appear. Click on that, and it will take you to System Properties.
3) In System Properties, click on the Advanced tab. Then click on Settings under Performance. This will take you to the Performance Options window.
4) In the Performance Options window, click on the Data Execution Prevention tab. Then select "Turn on DEP for all programs and services except for those I select:" Then, click Add. Find and select TS3W.exe. Then click Apply.
5) Restart Windows.

I'm back to Win10, and used the exact same TS3 folder that I had issues with, and now it works perfectly fine. Going by the principles of Linus Torvalds (never break user space), I think Microsoft is more at fault here than EA. But I don't really care as long as one or the other fixes this at some point, until Win10 reaches end of life.

I thought they fixed that DEP thing back in 1.36: https://www.thesims3.com/game/patches/440815388

But I guess it won't hurt to do that for people still in 22H2.

When I tried the game, I installed every update that was available at the time, which was yesterday, so yes I installed those as well. I don't think the game itself uses .NET Framework, I think it is just the launcher, since I remember being able to run the game itself (TS3W.exe) fine by just using DXVK on Linux, without .NET or Mono installed on the Wine prefix. I could be totally wrong though.

Anyway, I am out, good luck to everyone staying on Win11 22H2. Hopefully Win10's 22H2 will be less stressful. Thanks for all the help everyone!

---------------------

I have exactly the same issue with that fking win11 22H2 update, my game is on origin , 1.69 patch, and the DEP tip, antivirus exception, .NET doesn't help.
Sound like the only way to fix is to rolling back to previous update 21H2.

However, before to Save as in game, when I right click on Save Folder and Go to properties, When I uncheck the "Read Only" box and click on Apply and OK
and back to game to Save As I manage to Save but (Only ONCE with 50% of chance of success)

I decided to give Windows 11 22H2 a retry.

At this point, I've managed to be able to load the game normally and save without any issues.

First, I had to make sure that OneDrive is not running in the background. If it is, I get the "A serious error has occurred..." while loading the save.

Next one is going into Windows Defender and then to the Controlled Folders Access part. I turned that on and put TS3W.exe in the app exception list. I needed to do that after the "A serious error as occurred..." had returned about 12 hours after having gotten rid of it from closing out OneDrive. My last save had been written at about 11 PM last night, and the security updates were about 9 AM this morning.
After making those changes, the game started up fine, and I could save without any issues. This was also the case with Controlled Folders Access toggle switch off (though with TS3W.exe still in app exception list).

Lastly, I looked at DEP, and the settings didn't carry over from 21H2 (which I thought they had at first). So, I didn't worry about that since it's not relevant to the issue.



I checked and noticed that the folders in Documents on my computer have the Read-Only attribute as well.

I think the Error 16/problems opening saves could be a Permissions issue also.

Are you the lone user of your computer, or does it have multiple users?

---------------------------------
To reply to your question , I'm lone user of my system, and I always launch the game as administrator.

So judging by your post , you finally managed out the error code 16 error through Windows Defender steps and Controlled Folder Access on Windows 11 22H2 version right ?
Can you save properly with no error code 16 even each restarts of your system ?

I turned Controlled Folder Access On, and the "A serious error has occurred issue..." upon loading the save hasn't really happened since. So, I may be keeping that On from now on.

Although I never got Error 16, I wanted to see if I could get it to occur. I went to OneDrive, logged in, and set everything up there. I then started up the game and spent about an hour building on a lot. I then tried to save, and I got the Error 16. I closed out OneDrive from the "Show hidden icons" tab. I deleted the bad files, and I made another attempt to save via Save As. I got the Error 16 again.

Here is the next step I did. I opened up OneDrive again through the Start menu. Then, in Explorer, I right-clicked on the OneDrive icon to the left. Then I selected OneDrive -> Settings. Next, I clicked on the Account tab and then selected Choose Folders. I unchecked Documents from the list and clicked ok. I then closed out OneDrive via the icon on the hidden icons area, and I also made sure that it doesn't start upon boot-up. I was then able to save.

So, I rebooted the PC. Then I launched the game. The save loaded fine, and I played for about another half-hour. I was able to save without any issues. Then I exited the game.

The last security definitions update on Microsoft Defender was about 6 AM. At about 10 AM, I opened up the game again, and I had no issues loading the save. Before, this issue would seem to reoccur after a definitions update.