I need help on understanding what this means.

<?xml version="1.0" ?><root>
<BetterExceptions><BEversion>v3.13</BEversion><WasBlank>False</WasBlank><TuningLoadFinished>True</TuningLoadFinished><BadObjectCC>True</BadObjectCC><Advice>This is likely due to bad object CC. Check the Summary and Broken Mods section in BE Report.</Advice></BetterExceptions><report><version>2</version><sessionid>e8c1a99c3216346767afbc1b</sessionid><type>desync</type><sku>ea.maxis.sims4_64.15.pc</sku><createtime>2025-02-14 16:09:21</createtime><buildsignature>Local.Unknown.Unknown.1.112.519.1020-1.300.000.199.Release</buildsignature><categoryid>story_progression_action_sim_info_culling.py:450</categoryid><desyncid>e8c1a99c3216346767afbc1b</desyncid><systemconfig/><screenshot/><desyncdata>Exception in Sim Timeline: Exception running Element (KeyError: &lt;sim 'Elliana Guthrie' 0xf3c141c5e6806d4&gt;)&#13;&#10;Traceback (most recent call last):&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\scheduling.py", line 231, in simulate&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\alarms.py", line 293, in _run&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\story_progression\story_progression_service.py", line 335, in _process_next_action&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\story_progression\story_progression_service.py", line 353, in process_action_index&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\story_progression\story_progression_action_sim_info_culling.py", line 166, in process_action&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\story_progression\story_progression_action_sim_info_culling.py", line 450, in _process_background&#13;&#10;  File "T:\InGame\Gameplay\Scripts\Server\story_progression\story_progression_action_sim_info_culling.py", line 450, in &lt;genexpr&gt;KeyError: &lt;sim 'Elliana Guthrie' 0xf3c141c5e6806d4&gt;rtim=0&#13;&#10;Client Session Time: 274.56&#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: 13,396,0,5909&#13; &#10;Modded: True&#13; &#10;SystemInfo: Windows 11 10.0.26100 GPU: NVIDIA GeForce RTX 4060  32.0.15.7242, GUID: 6D90076B-E71B-11EF-9896-AC198E507944&#13; &#10;</desyncdata></report>
</root>

FnafGeek101 BE is guessing that your issue is caused by broken CC. I can't see a reason for that to be tied to culling, but you can test if just removing CC and deleting localthumbcache fixes it.

Otherwise, it would be helpful to know what was happening when the error occurred. And also if you've tested if the problem that happened happened with no mods or CC at all.

Note: Better Exceptions has its own Discord support.