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

did not work i got this exception: <?xml version="1.0" ?><root>
<report><version>2</version><sessionid>615f408a9755625d6937bdca</sessionid><type>desync</type><sku>ea.maxis.sims4_64.15.pc</sku><createtime>2025-12-09 00:14:35</createtime><buildsignature>Local.Unknown.Unknown.1.120.117.1030-1.200.000.685.Release</buildsignature><categoryid>developmental_milestone_tracker.py:1116</categoryid><desyncid>615f408a9755625d6937bdca</desyncid><systemconfig/><screenshot/><desyncdata>Exception raised while processing zone spin up sequence: 'Object not found: 0x8ae16e68' (KeyError: 'Object not found: 0x8ae16e68')&#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 1767, in update&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\zone_spin_up_service.py", line 1399, 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 1198, 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: 0x8ae16e68'rtim=0&#13;&#10;Client Session Time: 32.25&#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: 13,608,0,6121&#13; &#10;Modded: False&#13; &#10;SystemInfo: Windows 11 10.0.26200 GPU: Intel(R) UHD Graphics  32.0.101.7080, GUID: 0817F3B5-D191-11F0-AED3-C85ACFE91C0B&#13; &#10;</desyncdata></report>
</root>

Thank you, i'll try and get back to you

I have somik and oni's for foods and insimnia delivery. And no the previously modded one doesn't open with mods in 

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).

Start the game once with this in, then load your family, save the game, then remove the mod again.

Do make sure to create a backup.

<?xml version="1.0" ?><root>
<report><version>2</version><sessionid>ee182747ab6b627e693264b6</sessionid><type>desync</type><sku>ea.maxis.sims4_64.15.pc</sku><createtime>2025-12-04 22:52:57</createtime><buildsignature>Local.Unknown.Unknown.1.120.117.1030-1.200.000.685.Release</buildsignature><categoryid>developmental_milestone_tracker.py:1116</categoryid><desyncid>ee182747ab6b627e693264b6</desyncid><systemconfig/><screenshot/><desyncdata>Exception raised while processing zone spin up sequence: 'Object not found: 0x8ae16e68' (KeyError: 'Object not found: 0x8ae16e68')&#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 1767, in update&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\zone_spin_up_service.py", line 1399, 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 1198, 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: 0x8ae16e68'rtim=0&#13;&#10;Client Session Time: 29.66&#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: 13,603,0,6116&#13; &#10;Modded: False&#13; &#10;SystemInfo: Windows 11 10.0.26200 GPU: Intel(R) UHD Graphics  32.0.101.7080, GUID: 0817F3B5-D191-11F0-AED3-C85ACFE91C0B&#13; &#10;</desyncdata></report>
</root>

Re-downloading worked and the household now loads correctly again 👍

So an unmodded save opens fine, but the previously modded one doesn’t load into live mode? Did you use food mods and does the previously modded one open with mods back in?

(If it still doesn’t load even with the mods back in, take them out again and then check for a LastException as crinrict explained)

Hi 521204​ 

Do you have any LastException files in Documents\Electronic Arts\The Sims 4 ?

- Delete the ones you have
- Trigger the error again
- Check if new ones are created
- If that is the case, please copy/paste the content here. You can open the file with any text editor.

Deleting the file won't fix your issue. Posting the info is meant for troubleshooting. 

So the story starts, I bought dine out and when I went to go get a restuarant from the gallery, its saying all the restuarants are corrupt would I like to delete. I couldn't find a fix so I never played never saved the game from before I got dine out I just left it for a few days. A couple days later, I see new update, I updated my sims did everything right moved my mods folder out backed up y tray and saves update went perf. I start the game up with no mods in to test it out, first thing flashing black and white screen at open..okay it loads in. Then I click on play my family, perpetual loading screen once I click them from the manage worlds place. Okay, I discover the black and white screen is bcus my driver is not updated, I update it, repair my sims with cache and what not removed, emptied my tray and saves, mind u mods still not in there. I open sims with a fresh start no mods no old family, on the raw game it works and no more flashing black and white screen. Okay good, I then copy my tray and saves into the new sims4 folder and go to load up one of my families, same thing once I click play from manage worlds and from the main menu..perpetual loading screen. I'm so tired of this game please help.

Ahhh Got it!

So far that mod is working for me - my lastexception error had "milestone" in it so I searched for that. 

Thank you though!