Prepare for The Sims 4 September 22 Update even if Patch 1.128 has already started rolling out, especially if you use mods, custom content or an important long-term save.
Prepare for The Sims 4 September 22 Update by backing up the full Sims 4 user folder before your first post-patch save, launching once with mods disabled and checking creator compatibility before restoring script mods. The update is live, but the safest preparation steps still apply until you have tested your own game.
Prepare for The Sims 4 September 22 Update safely
Prepare for The Sims 4 September 22 Update Image Electronic Arts.
Prepare for The Sims 4 September 22 Update by closing the game completely and copying the full The Sims 4 folder from Documents > Electronic Arts to a safe location. A full copy protects saves, Tray files, mods, screenshots and configuration files together.
Back up the whole user folder first
A save-only backup is useful, but the full folder gives you more options if something goes wrong. Prepare for The Sims 4 September 22 Update with a clearly labelled copy such as “The Sims 4 Backup September 21 2026” and keep it outside the active Electronic Arts folder.
Do not use the backup as your working folder. The point is to preserve a known pre-patch state while you test the updated game.
- Close The Sims 4 and the EA app.
- Copy Documents > Electronic Arts > The Sims 4.
- Paste it to a separate folder or drive.
- Check that Saves and Tray are present in the copy.
- Keep the backup untouched until your main save is stable.
Move mods before the patch
Prepare for The Sims 4 September 22 Update by moving the Mods folder out of the active Sims 4 directory before installation. EA says outdated mod files were behind its largest automated crash report, so a clean test is more useful than immediately re-enabling everything.
After the patch, launch without mods first. If the base game opens and a disposable save behaves normally, you have a clean baseline before adding updated files back.
Do not save your main modded household too early
A save can load without its custom content and still be unsafe to overwrite. Prepare for The Sims 4 September 22 Update by testing in a new or disposable save first. If you open a household that relies on custom CAS items, objects or gameplay mods while those files are missing, exit without saving until compatibility is known.
Patch day checklist
Prepare for The Sims 4 September 22 Update with this order and you will know whether a problem comes from the patch itself, a particular mod or your user folder instead of changing everything at once.
- Install the update only after the backup is verified.
- Launch once with no mods.
- Check the game version and basic loading.
- Wait for creator compatibility notices for major script and UI mods.
- Remove old mod versions before installing replacements.
- Delete localthumbcache.package after changing mod files.
- Return mods gradually if you are troubleshooting.
How to verify the change after the update
Once the patch is installed, test Prepare for The Sims 4 September 22 Update in a backed-up or disposable save before changing several settings at once. Start without mods where possible, reproduce the exact behaviour the guide describes, and then restore compatible files gradually. This gives you a clean comparison between the official September 22 patch and anything being added by custom content or script mods.
If the result differs from the live Patch 1.128 behaviour, record the platform, game version and exact steps that reproduce it. Then repeat the test with mods removed so an outdated script or UI mod is not mistaken for a remaining base-game bug.
The September 22 update is now live as Patch 1.128. EA previewed the changes in its official September 15 Laundry List, and the live patch confirms the fix is included. If the same symptom continues, test an unmodded save before treating it as a failed base-game fix.
Prepare for The Sims 4 September 22 Update before installing the update
Prepare for The Sims 4 September 22 Update now rather than after a broken save, missing CC or crash forces you to troubleshoot under pressure. The best protection is simple: keep a full backup, patch with mods removed, test the vanilla game first and only restore files once their creators have checked compatibility.
