Load Error Code 800/801

I will add the following info, I'm going to say first I'm only about 60% sure that I'm correct on this,  but I think it worth investigating.

It looks like to me that the problem start in the following location:-

In the lot file you have something called architecture_bundle and inside that you have records.  This contains all the info about the lots.  One thing EA did when they made the sims 4 was to protect people from uploading other people lots to the gallery and claiming they own the lot, that is an example of one thing in them records files.  If you went into them files and changed the user name and tried to upload that lot to the gallery it would make sense, that suddenly you own that lot.  EA protected them files to what I can see, because if you edit them files they revert to what the files where previously.  The records also contain the venue info, in my case, the files from my Zone data did not update the architecture_bundle records correctly.

In game terms it's a common error that you change a lot type to say for example rental, but next time you load in the game it reverts the lot to residential.  That means Zone data does not always update  architecture_bundle records and this is more common the larger the save gets.  Just one last point in the Zone Data some lot types have different fields and you make a casual save while you exiting the game while watching youtube while waiting.  You trying to save onto a protected save file area with different data fields while not even in the game, possible with over 100GB of textures, it just not going to end well. 

Hi Skittle402​ 

thanks for the info. I'm currently trying to find out if everyone here has the same issue (don't think everyone is) and if it's still happening for new saves without any old data at all.

Your issue def sounds like what's being tracked here and in the 800/801 thread.

EA is looking into this.

You seem to be right if we start a new save file the issue doesn't occur unless we use items from the Gallery that contain enough data to bloat the save file size Clearly EA has neglected to update the engine it’s still stuck in 2014 back when hardware was weaker This forces developers to compress files so the game runs without issues on older PCs For the millionth time upgrade that failed engine All tests point to the game engine being weak so how can a demanding game run properly on such a poor engine?

I can say I've just spent the last two days fixing my corrupted save game, I can give you the following information I found.  I've had two corrupted games, both of the effected worlds started in Willow creek.  I used the sims 4 studio to replace the lots.  I think ground zero for the corruption started in a lot called Rindle Rose, I'm not 100% sure about this, but I did notice, the active_household_id_on_save had not reset correctly which caused cascading effect around the world of willow creek.  

So I was unable to load certain lots error 800/801, once you get the error, the game will not work correctly, it will stop other lots loading and you will get the endless loading screen.

The best thing to do at this point, is remove all the Sims from all the lots in that world,  and apply the fix, if you understand on how to use Sims 4 studio, then you need to make a fresh save export the damaged lots save from this save, change the Instance number and the zone ID and import them back into the corrupted save.  This will fix all but ground zero lots, to fix them lots you need to edit the zone date in the save game data file and reset the total to that to that of the working lot from the other save.  If needed i can do more detailed tutorial.

Some more information for you when you break down a save game file you find the following:

Based on 82GB Save Game

Save Game Data 36Gb All sim related stuff

Zone Object Data 164MB Lot Information

Game Lot Thumbnails 46GB Lot Thumbnails

Both of my corrupted worlds happened when my total size went above 120GB, when you first start a save the game uses the Thumbnails from it's own data file, but if you edit every lot in all worlds the total will be around 46GB added to your save file, this will get you closer to that danger zone.  

Also the next problem comes from textures that you download directly into your save game file, two types of files you can download

Tattoos  -  The Alpha images can be removed from the save game using Sims 4 studio and placed in your mod folder they will still work in game, but you should never share them sims on the gallery because the Alpha image will no longer be in your save game, I've currently got 81GB of Tattoos in my mod folder, working fine.  If added them Tattoos to my game file you can already see that, I would be well over the 120GB sweet spot.  Just a small point, this is how my save game was corrupted in the first place I got lazy one night and did a save while all my tattoos  in my save game. 

 Pictures - I can't get them to work in my mod folder, I usual just delete them, to stop it bulking out my save game folder, If I really like the picture I might make a custom object at least I can keep the pictures and it's not in my save game folder.

To fix this completely, EA need to change the save game file so it will Cache the Thumbnails and textures, leaving only the save game data, if they can't do that, the sims 4 studio can compress the save game file when you save, perhaps ea could make the game compress the save game, this would help reduce the size.

Hello,

I would like to report a save corruption issue that has been affecting my game for several months. I have spent many hours trying to isolate the cause, but I have not found a reliable solution.

Summary

Error Code: 800/801

Lots disappear after they have been loaded at least once.

This eventually affects lots across multiple worlds.

The issue only occurs in my existing saves. A completely new save currently does not reproduce the problem.

Timeline

I first noticed this issue around January 2026.

The first lot that disappeared in this save was Desert Bloom Park (Oasis Springs).

Later, many other lots became affected, including:

Cordelia's Secret Cottage (Henford-on-Bagley)

Copperdale High School

The High School Auditorium

The Carnival/Fairground lot from High School Years

Symptoms

The lot appears normally on the world map.

When entering the lot, it disappears completely in both Live Mode and Build Mode.

Error 801 may appear immediately while loading, or several seconds after the lot has finished loading.

If I restore the affected lot by placing the same lot from a healthy backup save through the Gallery after the lot has already disappeared, it works again temporarily.

However, if I place that Gallery copy before the lot has disappeared, it will eventually disappear again.

Because of this, I currently keep an older backup save only to restore disappearing lots.

Additional observations

The problem is not limited to residential lots.

Special lots are also affected, including:

High School Auditorium

High School Years Carnival/Fairground

For example, Copperdale High School did not disappear on the first school day (including the principal introduction event). Instead, it suddenly disappeared several in-game days later on an ordinary school morning.

The corruption appears to spread gradually. At first only one lot is affected, but eventually additional lots become corrupted.

Possible related issue: Neighborhood Stories

I also noticed another issue in the same save that may or may not be related.

Neighborhood Stories was configured as follows:

Played Households

All options disabled.

Other Households

Only "Adopt Pets" and "Join a Career" enabled.

Pregnancy, adoption, moving, deaths, and other progression options were disabled.

Despite these settings, NPC households continued to progress in unexpected ways:

Couples broke up.

Sims married different partners.

NPC households had babies.

I cannot confirm whether this behavior is related to the disappearing lots, but both issues occurred in the same save.

Mods

This save was originally played with the following script mods:

MC Command Center

MC WooHoo

Halapeco More Nihongo Names

Zero's Play As The Sages Generation

Zero's Play As The Sages (Japanese translation)

Sej FOMO

Maru Plantsim No Change Hair Leaves/Vines

While investigating, I also discovered that some MCCC settings were unintentionally left enabled:

Random Pregnancy value was set to 20.

Newborns were included in automatic NPC generation.

I have since corrected these settings, but I cannot determine whether they contributed to the save corruption.

Troubleshooting already performed

I have already tried the following:

Repairing the game through EA App.

Removing all Mods.

Testing without any CC.

Creating a completely new "The Sims 4" user folder.

Creating completely new save files.

The completely new saves currently appear to work normally.

Request

I have attached two save archives for comparison:Affected_Save.zip – the save after the corruption occurred.

Backup_Save_Before_Corruption.zip – a backup from before additional lot corruption occurred.

I hope comparing these save files may help identify the cause of the issue.

sent dm

You can find instructions here: General Information About The Bug Reports Forum | EA Forums - 4965007 

Hi crinrict​ 

It continuously is loading for hours without ending when entering build mode on a lot in a new save. After force quitting the game and restarting the game its stuck on the loading screen for 20 minutes before opening home screen.

unsure how to send a saved game.

I have the sane issue. I’ve been deal just with this for a week now. I can’t move into new houses. It all started when i deleted the NPCs.  Please help 

Hi amethystlw​ 

I merged your post with the main thread on 801.

Do you have issues on a new save too ? If not, would you mind sending me your save game ?

Upload it somewhere and DM me the link.