How to Update Sims 4 Mods After a Patch

After a Sims 4 patch, do not blindly launch your old mod setup and hope for the best. The safest approach is to back up your saves, check whether the game disabled mods, update the files you know need updates, and test in small batches before returning to normal play.

Quick update checklist

If you only want the short version, do this:

1. Back up your saves folder.
2. Launch the game and check whether mods were turned off.
3. Re-enable mod settings if needed.
4. Remove old versions of mods before adding updated ones.
5. Update any core frameworks or shared dependencies first.
6. Delete localthumbcache.package.
7. Test your game before restoring your full mod loadout.

If you are still new to the basics, keep the main install guide open beside this one.

Step 1: Back up your saves first

Before touching your mods folder, copy your saves folder somewhere safe. That gives you a recovery point if a broken update causes corruption, missing objects, or weird relationship and UI issues.

The folder is usually inside:

Documents/Electronic Arts/The Sims 4/

Step 2: Check whether the patch disabled mods

Official Sims 4 updates often switch mod settings off automatically.

Open Game Options -> Other and check:

• Enable Custom Content and Mods
• Script Mods Allowed

If those were turned off, switch them back on and restart the game.

Step 3: Remove duplicate or outdated versions

One of the easiest ways to break your game after a patch is leaving the old version of a mod in Mods while also dropping in the new one.

Before updating a mod:

1. Delete the old version.
2. Add the new version.
3. Confirm the file names make sense.

This is especially important for script mods, UI mods, and world replacements.

Step 4: Update dependencies before smaller mods

Some Sims 4 mods rely on shared injectors, libraries, or frameworks. If one of those breaks, dozens of other mods may seem broken too.

So the order should be:

1. core dependencies
2. major gameplay mods
3. smaller supporting mods
4. visual-only content like simple CC and map replacements

Step 5: Delete localthumbcache.package

After updating mods, delete localthumbcache.package from the main The Sims 4 folder. This file can hold onto stale references and make old behavior appear to linger after you thought you updated everything.

If you want the full explanation, read What Is localthumbcache.package?.

Step 6: Test in small batches

Do not restore 400 files at once and then try to guess what broke.

If the patch was major:

1. test with core mods only
2. add your heavier gameplay mods
3. add utility and UI mods
4. add visual CC last

This makes conflicts much easier to isolate.

Step 7: Watch for the most common post-patch symptoms

After a patch, these are the most common warning signs:

• the game disables your mods entirely
• UI panels look blank or broken
• custom interactions disappear
• objects vanish or reset
• the game loads but behaves strangely

If you see those, suspect outdated mods first, not your save file.

What usually survives a patch more easily?

Not every category is equally fragile.

Usually lower risk:

• simple clothing and hair CC
• furniture CC
• many map replacements
• basic visual overrides

Usually higher risk:

• script mods
• UI mods
• major gameplay overhauls
• mods with external dependencies

That does not mean visual mods never break, only that code-heavy mods usually need attention first.

What about Chatelain map replacements?

Chatelain map replacements are simple .package files, so they are usually easier to maintain than script-heavy mods. Even so, if a patch affects the same world or related assets, it is still smart to remove older versions before reinstalling updates.

Fastest safe recovery plan after a broken patch

If the game already feels broken, do this:

1. move your mods out temporarily
2. delete localthumbcache.package
3. launch the game once clean
4. close the game
5. add updated mods back in small groups

That gives you a clean baseline.

FAQ

Do Sims 4 patches always break mods?

No, but they often disable mod settings and can break script-heavy or UI-heavy mods. Simple visual content tends to be less fragile.

Should I delete old mod versions before updating?

Yes. Keeping old and new versions together is one of the most common causes of post-patch problems.

Why does the game act broken even after I updated a mod?

Because stale cache, duplicate files, or a missed dependency can still be interfering. Deleting localthumbcache.package and testing in small batches usually helps.

Should I test my existing save first?

Only after you have a backup. If you are nervous after a major patch, test in a throwaway save first.

Are map replacements usually safer after patches?

Often yes, because they are usually simple .package files, but they are still not immune to game changes.