[CC and Milestones, error code 110-578ef827] Stuck On Loading Screen Sims 4

Vamperix​  I've moved your post to the master thread for the milestones issue, which your lastexception lists.  Please install the mod linked in the accepted solution.

<?xml version="1.0" ?><root>
<report><version>2</version><sessionid>59d2c23aa171a15f68a8b6ca</sessionid><type>desync</type><sku>ea.maxis.sims4_64.15.pc</sku><createtime>2025-08-22 14:29:30</createtime><buildsignature>Local.Unknown.Unknown.1.117.227.1030-1.200.000.673.Release</buildsignature><categoryid>developmental_milestone_tracker.py:1114</categoryid><desyncid>59d2c23aa171a15f68a8b6ca</desyncid><systemconfig/><screenshot/><desyncdata>Exception raised while processing zone spin up sequence: 'Object not found: 0x2a1d81e6' (KeyError: 'Object not found: 0x2a1d81e6')&#13;&#10;Traceback (most recent call last):&#13;&#10;&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Core\sims4\utils.py", line 179, in wrapper&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\areaserver.py", line 222, in c_api_server_tick&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\zone.py", line 512, in update&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\zone_spin_up_service.py", line 1757, in update&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\zone_spin_up_service.py", line 1389, in on_update&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\zone.py", line 741, in on_hit_their_marks&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\zone.py", line 1142, in _set_zone_state&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Core\sims4\callback_utils.py", line 158, in __call__&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\developmental_milestones\developmental_milestone_tracker.py", line 1206, in send_all_milestones_update_to_client&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\developmental_milestones\developmental_milestone_tracker.py", line 1114, in _get_milestone_update_msg&#13;&#10;KeyError: 'Object not found: 0x2a1d81e6'rtim=0&#13;&#10;Client Session Time: 14.59&#13; &#10;Num Save Errors: 0&#13; &#10;Num Load Errors: 0&#13; &#10;Current Game State: 0x96d01090&#13; &#10;LoadingScreenActiveFlag: 1&#13; &#10;Origin Version: 13,535,0,6048&#13; &#10;Modded: False&#13; &#10;SystemInfo: Windows 11 10.0.26100 GPU: NVIDIA GeForce RTX 3080  32.0.15.8097, GUID: BDA88772-40F6-11F0-A2AB-806E6F6E6963&#13; &#10;</desyncdata></report>
</root>

last exception file from my game after the newest update tried repairing the game and deleting thumbcache, no mods or cc vanilla game but still having the same issue, back to the sims 3 i go :/

msnijder30​  From what I've heard, you should be able to remove the milestone fix mod once you save your progress with it present.

The reason for this error, the one that the mod fixes, is that when a sim achieves a milestone, some data references what object they used to do so, for example a playmat.  If the object is custom content, and you remove the cc, you won't be able to load that household.  So you could also just put back your cc objects to fix the problem.

And to be clear, it's not that you need to keep the item on the lot.  The point is that the game has to load the object in general, like in the Build/Buy catalog.

Hi, thank you so much for this. This is such an easy fix! Do I have to have these scripts in my game forever in order for it not to break?

My BF look into my game thru Sims 4 Studio, we did a lot of trial and errors, when he removed the Milestone Archived, my game worked. It took us 2 hours to figure out. 😪

msnijder30​  Try adding this mod, and reenable script mods of course:

https://www.patreon.com/posts/mod-milestone-81237568

It is possible that the milestone issue is secondary to the main one, that this mod will fix the milestone issue but still not allow your save to load.  So if it doesn't help, please post a new LE.

Samanthap19​ Kerrybubbles​  If you cannot load just the one household, but others work, please post a lastexception.  If you can't load any household, and you're bounced back to the worlds select screen instead, please use this thread if removing or disabling mods helps:

When Loading Save, Game Returns to Neighborhood Select Screen | EA Forums - 12488560

And this thread if it doesn't, or you never used mods with this save:

Cannot Load Into Lots after Aug 19 Update | EA Forums - 12489119

For the latter, please provide the info requested in the OP, and a save.  It's critical to get more information from users with this particular issue that doesn't resolve when mods are removed.

The same thing happens to me.  :(

At least yours still open 🥺🥺🥺 we just have to wait for modders to update their mods 🫶🏻 i think most of them is also trying to figure it our 

I'm having the same issue I removed my mods and it worked but playing without mods is so boring

Hi, I have deleted the first line of text. 

xQueenTora​  Please test with your Mods folder removed.  If it's happening in a new save, it's usually (although not always) mod-related.