In This Post
- Malicious Script Mods and Malware
- Mod Access: Folders/Mods Missing or Corrupted
- Loading, Saving, and Crashing
- Errors and Last Exceptions (LEs)
Malicious Script Mods and Malware
- Beginning as early as mid-January 2024, we began seeing Sims 4 script mods with malicious executable .exe code hidden in them. Shortly after that, we saw a case of fake mod updates being used to spread malware indirectly. Please see Malicous Script Mods and Malware for what you need to know about this. See How to Use Mods and CC for tips on safe sourcing of mods and CC.
Mod Access Problems
Unable to locate Mods folder
common causes:
- looking in the wrong folder
- multiple Mods folders (often caused by iCloud or OneDrive)
- folder was deleted or dragged out for testing and you need to relaunch the game to create a new one
For info on your Mods folder, see How to Use Mods and CC. For support, please head to Sims 4 PC Tech Support or Sims 4 Mac Tech Support.
Mods/CC not appearing
common causes:
Particular folders of CAS CC don’t show up in-game: For a few people, the patch 1.122 hotfixes did not fully resolve CAS CC not loading properly. This may especially affect people who moved their content onto an external drive. To resolve this, try manually making new folders and move the .package files into them. If this doesn’t work, the only alternative so far is to redownload the affected CC.
CC appears in Create-a-Sim (CAS) or Build/Buy mode but not in Live mode: you almost certainly have broken CC or are missing a required file.
File corruption
Known causes:
- Changing your folder contents while the game is running. Delete the corrupted files and obtain new versions. Make sure the game is completely finished shutting down before moving/deleting/adding files.
- External hard drives. This is less common.
The only known solution is to redownload mods/CC
Loading, Saving, and Crashing
Sims 4 loading issues
- Sims 4 not loading - known causes include:
- many outdated/broken mods/CC,
- non-Sims 4 .package files
- having multiple default replacement CAS mods in the same category
- GShade
- Sims 4 loads very slowly – mod-related issues include large Mods folders. Turning off the initial display of a mods list in Options can help to a point, but you might just need to start reducing your CC quantity
- Sims 4 loads only in DX9 mode – causes include non-updated Build/Buy items by simsi45 and several others. See the "Previously Broken" list, or do 50-50 testing of your Build/Buy mods. A batch fix is available in Sims 4 Studio.
World loading issues
- Specific World not loading: common causes include outdated versions of T.O.O.L Mod (TwistedMexi), Better BuildBuy (TwistedMexi)
- World Map not loading
Lot/Household loading issues
- Lot/household not loading for Live mode, "bouncing" to World Selection – This can be a game bug, but also can have mod-related causes. NOTE: Some causes will permanently corrupt a lot. Rule out mods before assuming it's a game issue; you might also need to load a different household and reload yours as part of testing. Causes include:
- Many outdated mods/CC, e.g.
- some Build/Buy items, noextramoneyonpromotion (Bienchen)
- many outdated script mods. For some of these, the last exception file generated (or Better Exceptions error file) will show you only one cause, but you might have many broken mods doing this. Start at the pinned lists.
- Specific to Windows: CC that is not updated for Direct X 11. Remove the CC, check at the creator's site for updates, or run a batch fix in Sims 4 Studio.
- Removing some CC/mods. This can cause specific households to not load In this category,
- cookbook/recipe mods removed without first deleting plates and food made with that mod (put the mods back and delete the plates/food);
- CC tied to Milestones - look for a Last Exception file with "developmental_milestone_tracker.py" (either put the CC back or use the bugfix mod Milestone Fixes by Lumpinou)
- outdated part-time career/freelance/"gig" mods
- Lot/household loading for Live mode, but only in DX9 mode – causes include non-updated Build/Buy items; see the list in the current pinned Broken/Updated Mods list, or 50-50 your Build/Buy mods; a batch fix is available in Sims 4 Studio
CAS loading issues
- endless loading of CAS – many causes and solutions covered in this post, generally related to Preferences mods
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Particular folders of CAS CC don’t show up in-game: For a few people, the patch 1.122 hotfixes did not fully resolve CAS CC not loading properly. This may especially affect people who moved their content onto an external drive. To resolve this, try manually making new folders and move the .package files into them. If this doesn’t work, the only alternative so far is to redownload the affected CC.
Saving issues
- Game saves only in DX9 mode – causes include outdated Build/Buy items; see the list in the current pinned Broken/Updated Mods list, or 50-50 your Build/Buy mods; a batch fix is available in Sims 4 Studio
- Crash during saving – causes include outdated/broken mods/CC, having over 8 Sims in a household
- Game doesn't save after 1.114 - causes include Child-and-younger sliders and presets
Crashing
- Last Crash report without crashing – likely cause: skeleton earrings by barbieaiden
- Crashing at the Main Menu – can be caused by removing custom tattoos (including CC) that a Mermaid is wearing. NOTE: This heavily impacts Mods folder testing but you can remove the save for testing too.
- Crashing in CAS – can be caused by:
- outdated mods/CC, including skeleton earrings by barbieaiden
- having over 8 Sims in a household
- Crash during saving – causes include oudated/broken mods/CC,
- Crash during loading – causes include:
- oudated/broken mods/CC
- last exception files ending in .tmp
- Other game crashing causes include:
- outdated CC, e.g. Aladdin Fabio Hair. However, there are many possible CC causes. If you get no crashing when testing vanilla (without mods/CC), you can use the 50-50 method to isolate problem mods/CC, or start at the pinned Broken/Updated Mods and CC list. More about how to test your mods and CC is in How to Use Mods and CC.
- Sims 3 CC
- over-high graphics settings for your computer
- old drivers
- old versions of Mac OS
- not enough RAM
- incorrect Gshade/Reshade installation
Error Codes and Last Exceptions (LEs)
Error codes after loading
Last exception (LE) files
If you have a "last exception" file or a similar error report from Better Exceptions or MC Command Center, you can find some info there that might point to mod/CC-caused problems.
- LEs in general – mod-related causes include duplicate files, missing pack requirements, broken/outdated mods. One cause of duplicate files is file-renaming by
- LEs on game loading re. "read only" – this is mod-related (after patch 1.105) but harmless
- LE and Sims in household disappear – Podcaster Career (QuietPriestess); remove this
- buff_Motives_Hunger_Starving_Ghost – known causes include outdated versions of roBurky mod Emotional Inertia (update this!), but also several package files, mostly body presets, that have it merged into them. Some that have been identified have creator names attached: HolisticSimmer, euno, and [AS].
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career_base. py… current_level_tuning – known causes include removing custom school/career mods: put the mods back in or try a “Save As”
- definition_manager.py / _load_definition_and_tuning / final_product - a change after patch 1.116 (July 1, 2025) specifically affecting custom food and woodworking recipe mods by several creators. Parts of the last exception near this text will give you an idea which file is your issue. Check with the creator for mod updates or other instructions, typically about new requirements.
- degree_tracker – this is sometimes mod-related and sometimes a game issue but usually caused by cheats; the linked thread includes instructions on how to use MC Command Center to fix Sims producing this error if it is caused by mods or cheats
- developmental_milestone_tracker – can indicate that a CC object tied to a Milestone was removed: either put the object back in the build or use the bugfix mod Milestone Fixes by Lumpinou
- drama_schedule_service failed, DramaNodeScoringBucket not 97, other DramaNode errors – causes include having removed freelance custom careers, "gig" mod, or phone invitation mods; this error rcan generally be fixed with a “Save As”
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fishing_location_component.py – caused by having a mod for a pack you don’t own, including files for Somik & Severinka - Realistic Cooking Mod (EA Override files), Srsly's EA Adjustments (New Prices version)
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guid64 – known causes include outdated career or university mods
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HasTunableReference - a script mod that needs updating for the 1.116 patch (July 1, 2025); this did not affect all script mods, but do check for updates if you're getting this
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holiday_service.py – often caused by removing a custom holiday; try a Save As to clear the error.
- load_from_persistable_sim_career_proto – known issues include removing school mods; try a “save as” in-game or play with the mod again.
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mc_career_dlg – caused by using the MC Command Center legacy version (which is for the game as it was in 2019), not the current version; delete the mod and reinstall the latest version
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min_lod_value – causes include outdated/broken custom traits; wrongly installed Andirz mods
- picker_interaction.py – causes include outdated PandaSama x Ravasheen toy kitchen; Piggy Banks, Oil Diffuser (Ravasheen); some Kritical objects
- restaurant_zone_director.py – mod-related causes include CC furniture in Restaurants
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scumbumbo_snippet – known causes include outdated versions of the SnootySims Camera mod; delete and redownload
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should_refresh_thumbnail – known causes include outdated Occult Hybrid Stabilizer/Unlocker mods or outdated 18+/NSFW mods
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sims4.tuning.instances.buff_Motives_Hunger_Starving_Ghost - known cause: outdated versions of roBurky's Emotional Inertia in merged package files, including ones with these names: Maycps, BodyPresetsMERGED, BodyPresetsMERGED_fixed, [HolisticSimmer] body preset f, euno Body preset (various numbers), [AS] Body Preset 3, [AS] Gina Body Preset, 03.package
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state_py with _do_first_time_state_added_actions – mod-related causes include Custom Music Channels Compatibility Fix by Staberinde (delete this)
- trait_tracker – often caused by outdated custom traits, custom aspirations, and complex mods that include traits
- tunable_model.py, get_model – often caused by having recipes but missing the recipe enabler mod, having an outdated recipe-enabler mod, or missing required packs
- tunable_perf (and also often TuningAttrCleanupHelper) – This error is caused by mods that were updated for a problem after Dec. 5, 2023 (1.103) ... and then Maxis fixed it on their end on Feb. 27, 2024 (1.105), so that mod fix now causes an error on game loading. This error is not an indication that there are other reasons the mod is incompatible with 1.105, but there could be other reasons. No error file can point you to which mods are the cause. Any script mods predating Feb. 27, 2024 should be checked for updates.
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UnavailablePackSafeResourceError – known cause: you have mods that require packs you don’t own or that you disabled. Check the files for the mod and the mod's instructions: sometimes only specific optional files need to be delected. Sometimes the whole mod isn't an option for you.
