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

It worked, thank you so much! ❤️

Armika74​  Please add this mod:

[CC and Milestones, error code 110-578ef827] Stuck On Loading Screen Sims 4 | EA Forums - 9309788

You may be able to remove it after saving with it present, but I've seen mixed reports about that.

<?xml version="1.0" ?><root>

<report><version>2</version><sessionid>10deee3d09ae9a1a699d4130</sessionid><type>desync</type><sku>ea.maxis.sims4_64.15.pc</sku><createtime>2026-02-24 07:17:21</createtime><buildsignature>Local.Unknown.Unknown.1.121.372.1020-1.300.000.234.Release</buildsignature><categoryid>developmental_milestone_tracker.py:1116</categoryid><desyncid>10deee3d09ae9a1a699d4130</desyncid><systemconfig/><screenshot/><desyncdata>Exception raised while processing zone spin up sequence: 'Object not found: 0xdc0a39a3' (KeyError: 'Object not found: 0xdc0a39a3')&#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\sims\masked\v187.16\injector.py", line 26, in _wrapped_function&#13;&#10; File "T:\InGame\Gameplay\Scripts\Server\sims\masked\v187.16\zone_tick.py", line 83, in _turbolib_zone_game_update&#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 1881, in update&#13;&#10; File "T:\InGame\Gameplay\Scripts\Server\zone_spin_up_service.py", line 1513, 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 1211, in send_all_milestones_update_to_client&#13;&#10; File "T:\InGame\Gameplay\Scripts\Server\developmental_milestones\developmental_milestone_tracker.py", line 1116, in _get_milestone_update_msg&#13;&#10;KeyError: 'Object not found: 0xdc0a39a3'rtim=0&#13;&#10;Client Session Time: 43.85&#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: 13,649,0,6162&#13; &#10;Modded: True&#13; &#10;SystemInfo: Windows 10 10.0.19045 GPU: NVIDIA GeForce GT 730 30.0.14.7514, GUID: C841D1B9-FB98-11EC-9C1F-10604B700981&#13; &#10;</desyncdata></report>

</root>

Armika74​  Please open Documents > Electronic Arts > The Sims 4 and delete any lastexception files you see.  Try again to load this household, and when it doesn't work, look for a new LE.  If you find one, open it (Notepad is fine), copy the text, and paste it into a reply here.

If you don't see a new LE, that's also useful information.  In that case, let me know whether you can load a previously-unplayed household in that save.

Edit: I deleted the Sims 4 folder and started a new game and then it works, but not with my old save file. 3rd gen down the drain or what?😥

When I try to get into my game it gets stuck on the loading screen. I have removed my mods and repaired the game but it still won´t work. Anyone who knows what to do, I am at my wits end 😫

Yeah I tried that as well while I was waiting for a reply, but that didn't help either, luckily the mod fix did help. But I'm already scared of another patch they might push out for the new ep

This fixed it, thank you so much to all of you

I had this issue (no mods) and ultimately had to delete the two infants to be able to load into the family in live mode.

Hi chofam01​ 

you seem to have an issue with a milestone that was on a cc that you removed from the game.

Try this mod: https://www.patreon.com/posts/mod-milestone-81237568  (File 2: CC/Mod Object Fix).