The Sims 4 Not Starting: How to Fix

I’m told The Sims 4 is a great game. I don’t play it myself, but my daughter has more hours on it than she’s probably spent doing homework. No, not probably. Definitely. And I’ve probably spent nearly as much time fixing the damn thing.

You see, if you play The Sims 4 on PC or Mac, you can add third party content, known as “mods”, “scripts” or “custom content” (CC). This is (or rather should be – long story, but let’s just say it’s a heated debate in the Sims community) free and, let’s say, my daughter has a few of them (15,000 at the last count, each of them being a separate file. Urgh).

EA doesn’t guarantee that their updates won’t break due to someone else’s mod, so often that’s exactly what happens. And you’re then left hunting the thing down.

This week, though, no update occurred but, none-the-less, her game stopped working. Rather than something in the game break, the game itself just refused to load. I fixed it after about 2 hours of work and I have no idea even now what the cause was or, in fact, how I did fix it. None-the-less, I thought I’d share some useful resources and ideas on what others can do. Particularly stressed parents in the same situation.

Oh, and this is for the Mac, but Windows works in much the same way.

The Problem

Within the EA app, we launch The Sims 4 and EA minimises, a few seconds goes by and it then re-appears. And all without The Sims 4 actually starting.

I’d show screenshots, but there’s literally nothing to show other than something not happening.

Repairing the Foundations

Read any instructions on how to fix, the first thing they’ll recommend you do is repair the game, which you can do from the EA launcher – click the dots next to the Sims 4 start button and you should have an option to do it.

It validates the game files to make sure all the main code (the stuff that isn’t unique to you) is as it should be. I’m not sure this has ever fixed any of the issues I’ve come across and it didn’t here. But it’s worth a try.

Finding Your Sims Files

The Sims 4 creates a folder in your Documents directory called Electronic Arts, under which is The Sims 4. All your unique content is under that and consist of both files and folders.

lastCrash.txt

This file is in the main Sims folder and is created if the game crashes. The file creation date will be current if this is the case, which it was in my case. It’s a text file but reading it, it won’t make much sense to most people. However, upload it to ChatGPT and ask it to interpret it for you, and it will give you a much better idea of any issues.

This is what it told me for my issue…

The repeated entries:

'Metal' ... 'AGXMetal13_3'

point to Apple’s Metal graphics driver (AGXMetal13_3 is the GPU driver layer for M1 chips).
This means the crash occurred within GPU rendering code, not general gameplay logic.

Since the crash happened while LoadingScreenActiveFlag: 1, the game was still loading assets — textures, meshes, or shaders — when it failed.
When combined with Modded: True, this pattern almost always means:

💥 One or more custom content (CC) textures, CAS parts, or build items used unsupported or malformed textures/materials that the Metal renderer couldn’t compile or allocate memory for.

To be fair, if you have mods installed, pretty much all crash reports will come back to this in my experience. Indeed, before using ChatGPT I tried it with Google Gemini and it just went straight for the “you have mods active, so it will be that” answer.

Based on the crash report, the issue is that your game has mods installed, and one or more of them are likely outdated or conflicting with the game, causing it to crash on startup.

The report explicitly states Modded: True1. The crash also happens very quickly after launch (around 11 seconds, according to the Client Session Time 2), which is classic behavior for an incompatible mod problem.

The thing is… it wasn’t. You can test this by renaming the mods folder out of the way. I did that and it still failed just the same.

Starting afresh

With no idea at this stage what it could be, it’s time to narrow it down further. In this I renamed the whole The Sims 4 folder. This isn’t required, as it just hold your personal data – it’s not required to run the game.

So I did that and clicked on the button to start the game and…. it started! Albeit now a clean version with no saved games or personalisation.

That shows that it’s something to do with the content of that folder if nothing else.

The next step was to start copying back the content from the old folder to the new one – a couple at a time before testing each time. Do mods last. You can ignore any files or folders to do with caching but make sure to copy any settings files over, as well as obvious folders such as the saved games, screenshots, videos, etc.

Each time I tested it was still fine and I was eventually just left with the mods folder to copy over.

I did this and…. it started. But hung on the loading screen. I know she has a lot of mods but I walked away and left it for 20 minutes and it stopped progressing, which certainly isn’t right.

I force closed it and went back to the mods folder, as all of this suggest that, after all, AI was right – a mod is causing this. This is when you need to know how to do a binary chop.

I halved the mods file and tried it – it worked. Then, for no apparant reason, I decided to test the other half without reducing it down further. And that worked. Both halves worked just fine. That’s… odd.

I put them back together and tried… it worked. It loaded! WTAF.

Now, everything was back to how it was before I started testing the mods, when it previously refused to load.

What happened?

I have some theories.

The more I read on the subject, the more I think the issue may have been down to the cache files that I hadn’t copied over to the new The Sims 4 folder. A lack of caching (which speeds things up) may have caused the lock up. Maybe I was too impatient.

The other option is something I hadn’t mentioned here. After renaming the mods folder out of the way near the end and getting it to start successfully, I checked the settings screen and noticed that scripts were turned off (scripts are different to mods – mods add new content, whereas scripts run actual code. Confusingly they’re all stored in the mods folder). I turned them back on. Now, if a script was the cause I would have made it worse, but wanted to make sure I cured all the issues, so made sure this was on. This shouldn’t have made it better.

But, let’s go back to the original issue. It wasn’t even getting to the loading screen and was crashing really early. It wasn’t the mods folder, I don’t think, as I renamed that out of the way earlier and it still failed. I wonder if one of the settings file had corrupted. Going into settings and switching scripts back on may have caused the settings file to get written to and correct. Something else which suggests this may be the case is that the resolution was wrong and scripts were turned off (my daughter had them turned on) – considering I’d copied over the settings, this shouldn’t have been the case.

I have the original folder still so could test and fully work it out but for the sake of my daughter’s (and my) sanity, I’m not going to touch it now. She says everything is as-was, but I’m keeping the copied away folder for a few weeks, just in case.

Useful Links

If you’re experiencing issues with The Sims 4, these are some incredibly useful links for getting to the bottom of them…

• EA’s official Sims 4 forum – there are technical sections for Mac, PC and consoles
• Reddit’s Sims 4 sub – particularly, look at the pinned discussions at the top, which include known issues
• The Mod List – a list of mods and known issues with them (really helpful if you believe a mod may be causing your issues)