Before you start

  • This guide is for mod-related issues. Base game bugs are separate.
  • Work slowly, test often, and back up your data first.
  • Give creators time to update. Many modders live in different time zones and have jobs or school.

1) Update script mods first

Script mods are most likely to break after patches.

  • Check trusted trackers like Scarlet’s Realm for broken and updated mods.
  • Visit creators’ sites, Patreon pages, or Discords for current builds.
  • If in doubt, re-download to ensure you have the latest version.

2) Test the game with zero mods

Prove whether the issue is mod related.

  • Move your entire Mods folder to a temporary folder on your desktop.
  • Delete Documents\Electronic Arts\The Sims 4\localthumbcache.package.
  • Launch the game, click through the “Items Removed” prompt, and reproduce the issue.
  • If the problem is gone, a mod is the cause. Do not save this test file.

3) Use the 50-50 method

Narrow down problem files with process of elimination.

  • Split your mods into two groups. Add one half back to Mods.
  • Delete localthumbcache, launch, and test.
  • If the issue appears, the bad mod is in that half. If not, it is in the other half.
  • Keep halving the suspect group until you identify the culprit.
  • Update or remove broken mods and any obsolete files you no longer need.

4) Remove or replace problem mods

If a creator confirms a mod is broken or unmaintained, remove it.

  • Look for maintained forks or alternatives if you rely on that feature.
  • Keep a notes file that lists what you removed and why.

5) Repair the game if needed

Use this if your game misbehaves even without mods.

  • First back up your Saves and Tray folders to a safe location.
  • In the EA App or Steam, run Repair on The Sims 4.
  • Reapply any manual file tweaks after the repair completes.

6) Consider playing offline on patch day

Want to avoid the scramble after updates

  • In the EA App, choose Go Offline to stop auto updates until mods catch up.

7) Use Better Exceptions as a helper

TwistedMexi’s Better Exceptions can scan after a patch and flag potential incompatibilities.

  • Treat results as a guide, not absolute truth. False positives can occur.
  • Always verify against creator posts or trackers before deleting anything.

8) Re-enable mods after patches

The game may disable mods after updates.

  • In Game Options, turn Enable Custom Content and Mods and Script Mods Allowed back on.
  • Quit without saving, relaunch, then continue testing.

9) Good habits that prevent headaches

  • Keep a clean folder structure by creator and mod type.
  • Store a text changelog of new installs and updates.
  • Back up Saves and Tray regularly.
  • Update one creator’s set at a time and test before adding more.
  • Always delete localthumbcache after adding, removing, or updating mods.

Quick troubleshoot checklist

  • Updated script mods from creator sources
  • Game launches clean with no Mods folder
  • 50-50 method used to isolate conflicts
  • Obsolete mods removed
  • Repair run with Saves and Tray backed up
  • Offline mode used on patch day if needed
  • Better Exceptions scan reviewed and verified
  • Mods re-enabled in settings after patch

Source – itsmeTroi: https://www.youtube.com/watch?v=8pRU7sGkEUk&ab_channel=itsmeTroi

Sims 4 Broken Mods Folder – FAQ

Why do my Sims 4 mods break after updates?

Major Sims 4 patches often change the game’s code. Script mods are especially vulnerable, while custom content (CC) sometimes breaks too.

What is the first thing I should do after a patch?

Check for updated versions of your mods, especially script mods. Use trackers like Scarlet’s Realm or go directly to creators’ Patreons, Discords, or websites.

What is the localthumbcache file and why should I delete it?

localthumbcache.package stores cached mod data. If it’s not deleted, the game may load outdated code and cause issues. It regenerates automatically when you restart the game.

How do I test if my mods are the problem?

Move your entire Mods folder out of the Sims 4 directory, delete localthumbcache.package, and launch the game. If the game runs smoothly, the issue lies in your mods.

What is the 50-50 method?

A troubleshooting process where you split mods into halves, test each half, and continue halving until you isolate the broken file(s).

What do I do with broken or obsolete mods?

If a mod is outdated and unmaintained, remove it. Replace it with updated versions or alternatives from other creators.

What if my game is still broken without mods?

Back up your Saves and Tray folders, then run Repair Game from the EA App or Steam. This restores missing or corrupted files.

How can I avoid chaos on patch day?

Use the Go Offline option in the EA App to delay updates until creators confirm their mods are safe.

What is Better Exceptions?

A tool by TwistedMexi that scans your mods after patches and flags potential issues. It can help, but sometimes shows false positives. Always cross-check with creators.

Why did my mods disappear after updating?

Some Sims 4 patches automatically disable mods. Re-enable them under Game Options > Other > Enable Custom Content and Mods and Script Mods Allowed. Then restart the game.