Sims 4 Mod Conflict Detector: Tools That Still Work

Conflict, duplicate or broken: know which one you have

A conflict detector answers one question: do two of my mods change the same thing? Every piece of Sims 4 data (an interaction, a trait, a recipe, a CAS part) has a resource key. When two packages contain the same key, or two script mods replace the same game code, only one change can win. The other mod silently stops working, or both misbehave.

Most "my mods conflict" problems after a patch are really broken mods. Rule that out first: if the problem started on patch day, check the current Broken and Updated Sims 4 Mods and CC thread on EA Forums before hunting conflicts.

Every Sims 4 mod conflict detector, checked November 2026

The older standalone detectors read .package files only. They cannot see conflicts inside .ts4script files, which is where many modern gameplay conflicts live. EA Forums helpers put it bluntly: those tools are reliable for duplicates and stray files, not for real conflicts. Better Exceptions is the only one of these still maintained.

How to run the Better Exceptions conflict scan

1. Download Better Exceptions from TwistedMexi's mods page or CurseForge. Avoid reuploads; old versions circulate.
2. Put the .ts4script file in Documents\Electronic Arts\The Sims 4\Mods (Mac: ~/Documents/Electronic Arts/The Sims 4/Mods), no more than one subfolder deep.
3. In the game, Game Options > Other: tick Enable Custom Content and Mods and Script Mods Allowed. Restart.
4. Load a household. Click the Better Exceptions welcome notification.
5. Open the Better Exceptions menu and choose Check for Conflicts.
6. Wait. The scan takes several minutes, longer with a big Mods folder or a hard drive instead of an SSD. The report opens in your browser when it finishes.

Run it when you suspect a conflict, after installing a batch of new mods, or as a cleanup every few months. It is slow, so it is not something to run every session.

Reading the report and fixing each conflict

The report is a table with File A and File B columns. Each row is one pair of files that conflict. Expand a row to see the exact resources both files change. The bottom of the report shows how many conflicts were found out of how many files.

• Green "Intentional Override" badge: the files are meant to overlap, for example an add-on that patches its parent mod. Hover for the explanation. These can usually be ignored.
• Two unrelated mods: decide which one you want more and remove the other. Remove the whole mod (every package and script file that belongs to it), not just the one file named.
• Two mods that do similar things (two pregnancy overhauls, two career overhauls): pick one. These rarely work together.
• Check the creators' pages. Many creators list known conflicts and sometimes publish a compatibility patch that lets both mods run.

Better Exceptions never deletes anything for you. After removing files, delete localthumbcache.package from the The Sims 4 folder and restart.

Finding duplicate CC and stray files

Duplicates do not usually crash the game but they bloat load times and can show the same item twice in CAS or Build Mode. For this job the old tools still help, because duplicate files do not change with patches.

• Mod Conflict Detector (Windows): finds duplicates, non-Sims 4 files and stray files, and can disable chosen mods. It is unmaintained since 2018, so ignore its conflict results for script mods.
• Sims Mod Assistant: finds exact copies saved under different names and groups probable CAS, skintone, slider and catalog conflicts, with an option to open a file in Sims 4 Studio.
• By hand: sort your Mods folder by size, then by name. Files with identical sizes and similar names are often the same download saved twice.

Remove Sims 3 files (.sims3pack, .package files made for Sims 3) and anything that is not a .package or .ts4script file. Unzip archives; the game does not read .zip downloads.

When the detector finds nothing: the 50/50 method

No detector catches every conflict. Some mods clash only in play, for example two mods that both change the same Sim behavior through different files. EA's own method finds those.

1. Back up Saves. Move your whole Mods folder to the desktop.
2. Start with gameplay and script mods. EA notes they cause problems far more often than CAS or Build/Buy CC.
3. Put half back, delete localthumbcache.package, launch and test.
4. Problem returns: the culprit is in that half. Problem gone: it is in the other half.
5. Keep halving until one mod is left. If the problem only appears with two specific mods together, you have found a true conflict.

Exit without saving each round, or use a test save, so your main save is not changed.

Conflict detector not working? Fixes

• Better Exceptions menu never appears. Tick Script Mods Allowed, keep the .ts4script file at most one folder deep, and make sure mods were not switched off by a game update (Game Options > Other).
• Better Exceptions is outdated. After a new patch, check its download page for the game version it was built for and grab the newest release.
• Mod Conflict Detector will not open or reports thousands of conflicts. It has not been updated since 2018. Use it only for duplicates and stray files.
• On Mac. Mod Conflict Detector is Windows only. Use Better Exceptions, which runs inside the game. Treat any "Mac version" of Mod Conflict Detector on a random site as unsafe.
• On PlayStation or Xbox. Console versions of The Sims 4 do not support mods, so conflicts cannot happen.
• Error code 102, 123, 125, 127, 129 or 131. EA links these to the game's script, so suspect a script mod. Error 110 usually means outdated mods after an update.

Want a life sim with nothing to conflict?

Conflicts are the cost of building your own game out of hundreds of mods from different creators. If you would rather just play, LifeSim is a free online life simulator that runs in your browser on a computer or phone, with no download and no packs. You can be anyone in any real city on Earth and live a life day by day: characters have needs, jobs and relationships, and the townspeople around you are AI-driven. There is no Mods folder, so there is nothing to scan.

Safety notes

• Download conflict tools and mods only from the creator's page or CurseForge. EA and Maxis do not screen mods.
• Mod The Sims accounts have been compromised in the past to upload malicious files. TwistedMexi's free ModGuard blocks known compromised mods.
• Back up Saves and Tray before removing mods. Removing CC from a saved household can strip those items from Sims and lots.

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