How to Fix Broken Mods After a Sims 4 Update

First: The Golden Rule You Needed Before Updating

If you're reading this after already updating and things are broken, this section is for next time. If you haven't updated yet after seeing a patch notification, this section is for right now.

The golden rule for heavily modded Sims 4 players: do not update your game immediately after EA releases a patch. Wait at least 48–72 hours. During that window, the Sims modding community will identify which mods are broken, creators will begin releasing compatibility updates, and community-maintained broken mods lists will populate with accurate information. Updating immediately means potentially running broken script mods before their creators have had a chance to fix them — which is how you end up with last exception errors in your save file or, in worst cases, save corruption.

On PC via the EA App or Steam, you can often delay the update by simply not launching the game after the patch releases. Once you've confirmed your critical mods (especially MCCC and any other script mods you run) have released compatibility updates, then update.

Step 1: Identify Whether Mods Are the Problem

Before troubleshooting mods specifically, confirm that mods are actually causing the issue and not the game update itself. Move your entire Mods folder temporarily out of the Sims 4 directory (don't delete — move it to your Desktop or a temporary location). Launch the game without any mods or CC. If the game runs cleanly, mods are the cause. If the game still crashes or behaves incorrectly without mods, the issue is with the game update itself — check EA's official forums and the community subreddit for reports of the same problem.

Once you've confirmed mods are the cause, move your Mods folder back and proceed to identification.

Step 2: Check the Broken Mods Lists

After every major EA patch, the Sims community assembles broken mods lists — community-maintained resources that track which mods are confirmed broken, which are confirmed working, and which are pending creator updates. These lists save enormous amounts of troubleshooting time. The most reliable sources:

• Carl's Sims Guide — maintains a regularly updated patch compatibility tracker at carls-sims-guide.com. This is the most comprehensive and consistently maintained resource in the community for this specific purpose.
• r/TheSims subreddit — typically has a pinned post or megathread after major patches tracking mod compatibility. Community-sourced but fast to populate.
• Individual creator pages — Tumblr blogs, Patreon posts, and Discord servers for your specific mods are the most accurate sources for those particular mods. Deaderpool's MCCC Discord is especially fast with compatibility information after patches.

Cross-reference these sources against the specific mods you're running. Make a list of mods confirmed broken versus confirmed working. This gives you a targeted removal list rather than requiring you to troubleshoot everything at once.

Step 3: Remove Confirmed Broken Mods

For any mod confirmed broken on the community lists, remove it from your Mods folder before loading any save. Do not just leave a known-broken script mod in your folder and hope for the best — a broken script mod can generate last exception errors that accumulate in your save file and cause instability. Move broken mods to a temporary folder outside the Mods directory rather than deleting them; you'll want to swap them back once updates are released.

For mods not on any list (smaller mods, older CC mods that community trackers don't cover), proceed to the 50/50 method if you're still experiencing issues after removing known-broken mods.

Step 4: Clear Your Cache Files

After any game patch and after removing broken mods, clear your game's cache before the next launch. Navigate to your Sims 4 root folder (Documents/Electronic Arts/The Sims 4) and delete localthumbcache.package. Also clear the contents of the cache subfolder (you can delete everything inside it; the game regenerates cache files automatically). This ensures the game isn't loading any pre-patch cached data that might conflict with the updated game state.

Step 5: The 50/50 Method for Unknown Problem Mods

If you're still experiencing issues after removing confirmed broken mods and clearing cache, you have a mod that's broken but not on any community list yet. The 50/50 method isolates it efficiently:

1. Move half your remaining Mods folder contents into a temporary folder.
2. Launch the game and test. If the problem persists, the culprit is in the half still in Mods. If the problem is gone, it's in the half you removed.
3. Take the guilty half, split it in half again, repeat.
4. Each cycle halves the candidate pool. With fifty mods, you isolate the problem in six or seven test cycles.

This is tedious but completely reliable. It works for script mod conflicts, broken CC conflicts, and mod interaction problems equally well. Once you've isolated the specific file, remove it and check the creator's page for an updated version.

Step 6: Load a Backup Save for the First Post-Patch Test

Before loading your main long-term save after a patch and mod recovery, load a backup save or a throwaway save first. Verify the game runs cleanly, mods are functioning correctly, and no new last exception errors are being generated. Only after confirming stability in the test save should you load the save you care about.

The Sims 4 automatically maintains several rolling backup saves in your Saves folder — files with suffixes like .ver0 through .ver5. These are your recovery points if a main save gets corrupted. Knowing they exist and how to access them is important before you need them.

Keeping a Mod Inventory

One practice that makes patch recovery significantly faster: maintain a simple text file listing every script mod you currently run, the creator's name, and where to find their updates (Tumblr URL, Patreon link, website). When a patch hits and you need to check ten script mods for compatibility, having that list means the process takes minutes rather than an afternoon of searching for creator pages you can't quite remember.