How It Works
Sims 4 Mod Fixer runs locally on your computer. Nothing is uploaded, nothing is sent anywhere. Every action it takes is reversible.
Point it at your Mods folder and it reads every .package and .ts4script file, including inside nested subfolders — and looks inside each .ts4script archive itself. It builds a complete picture of what you have, what depends on what, and where things overlap. Tested with folders over 10,000 mods.
This is where it goes deeper than other tools. It doesn't just check if files are corrupted. It checks if they'll actually work with your current game version.
- Patch compatibility analysis — Detects mods that reference game features removed by a patch. Catches problems before you launch, not after a crash.
- Crash log reading — If you've already crashed, it reads your lastException files and tells you exactly which mod caused it. By name.
- Game settings check — The #1 reason mods stop working after a patch is that the game silently disables mod support in your settings. This catches and fixes that in one click.
- Script mod deep scan — Script mods (.ts4script) are the #1 source of crashes and Error 109. Scans inside them for version mismatches and broken dependencies, and flags hidden executable files (.exe, .dll, and similar) bundled inside the archive.
- Conflict detection — Finds mods trying to change the same game resources, which causes unpredictable behavior.
- Duplicate finder — Finds exact copies and same-name-different-version duplicates wasting space and causing confusion.
- Source tracking — Identifies where your mods came from (CurseForge, ModTheSims, The Sims Resource, Patreon) so you can quickly check for updates from the original creator.
One-click auto-fix for everything it finds. Every mod it flags gets quarantined, not deleted. Moved to a safe folder outside your Mods directory with a full log of what was moved and why. Restore anything with one click if it got something wrong.
A built-in guided 50/50 tool automates the process. No spreadsheets, no renaming folders. It remembers where you left off even if you close the app.
Your Mods Are Safe
- Never deletes your files. Ever. Only quarantines.
- Never uploads or shares any of your data.
- Never modifies your mod files — only moves them.
- Doesn't require admin permissions or special access.
- Full operation log so you can see everything it did.
- One-click restore to put anything back exactly where it was.
Who Made This
Sims 4 Mod Fixer is built by an independent developer who got tired of losing whole evenings to the manual 50/50 method. It started as a personal tool and grew into a full diagnostic engine: a custom parser that reads DBPF .package files and a reader that parses .ts4script Python bytecode, so it checks whether your mods actually work with your current game version instead of just looking at file names. It is the only Sims 4 tool that combines scanning, fixing, conflict isolation, duplicate cleanup, update tracking, and malware screening in one app.
It has been tested on real-world setups, including a 13,000-mod, 82 GB folder that scans end to end in about four minutes. It runs entirely on your computer, never deletes a file, and is not affiliated with or endorsed by Electronic Arts.
Frequently Asked Questions
How do I fix broken mods after a Sims 4 update?
Download and install Sims 4 Mod Fixer, run a health scan on your Mods folder, and it tells you exactly which mods are broken by the patch. The auto-fix feature quarantines broken mods so your game runs while you wait for mod updates. Restore anything with one click.
Is it safe to use?
Yes. It never deletes any files. All fixes use a quarantine system that moves mods to a safe vault outside your Mods folder. You can restore anything with one click. Nothing is uploaded or sent anywhere — it runs entirely offline on your computer.
How is this different from the 50/50 method?
The 50/50 method means manually moving half your mods, launching the game, and repeating for hours. Sims 4 Mod Fixer scans every mod file directly and identifies broken mods in minutes without launching the game. It also has a smart 50/50 tool that automates the process for mods that can only be tested in-game.
Does it work with CC (custom content)?
Yes. It scans all .package and .ts4script files, including CC, script mods, and tuning overrides.
What's the difference between this and Better Exceptions?
Better Exceptions is an in-game mod that diagnoses crashes after they happen. Sims 4 Mod Fixer runs before you launch and prevents crashes by identifying broken mods proactively. They complement each other.
Free Sims 4 Mod Guides
Complete Sims 4 Mod Troubleshooting Guide
Why mods break after patches, how to read crash logs, the 50/50 method, and fixes for the most common errors.
How to Fix Broken Mods After the March 2026 Patch
What the Marketplace update changed, which mods were affected, and how to get your game running again.
Any features you would like to see? We'd love to hear from you! [email protected]
$9.99 — one-time purchase, not a subscription