Sims 4 Unable To Start There Was An Error Processing The Startup Configuration Script Exclusive __full__ Jun 2026

In the EA App or Steam, right-click the game and select Repair .

If you have ever attempted to edit your graphics rules for better performance or used custom lighting mods, this is likely the cause. Navigate to Documents > Electronic Arts > The Sims 4 . Open the folder. Delete everything inside this folder. Try launching the game again.

Delete the localthumbcache.package file in your Sims 4 folder.

The primary reason for this error is . These are most likely:

Split your mods into two halves. Test one half in the game. Repeat this process until you pinpoint the exact file causing the crash. 2. Repair Game Files via Your Launcher In the EA App or Steam, right-click the

: If using Windows Defender, type "Controlled Folder Access" into your Windows search bar. Temporarily toggle it off, or explicitly allow the Sims 4 application through the block list. Step 4: Isolate Corrupt Mods or Local Cache

: Open your antivirus settings (or Windows Defender ). Add an exception or exclusion rule for the game executables ( TS4_x64.exe and TS4_DX9_x64.exe ).

While this specific script error points to graphics or configuration parameters, heavily outdated script mods can still force initialization failures.

This error indicates that the game cannot read or execute its internal startup script (likely a Lua or Python configuration file) due to a . It is rarely caused by hardware issues and is almost always software-related—often due to mods, broken game files, or permission problems. Open the folder

If you are seeing the error: , you are not alone. This specific error has plagued players since the Horse Ranch and For Rent expansions, but it continues to appear after patches, game updates, or mod installs.

Wait for the verification process to finish before launching. Open and go to your Library . Right-click The Sims 4 and select Properties . Go to the Installed Files tab. Click Verify integrity of game files . 3. Regenerate the Sims 4 User Folder

The most common cause of this specific error is an incompatible or corrupted file in your ConfigOverride Navigate to: Documents > Electronic Arts > The Sims 4 > ConfigOverride Delete everything inside this folder. Note for Mac Users: Since the January 2025 patch, placing a copy of GraphicsRules.sgr in this folder will trigger this error immediately. 2. Repair the Game in the EA App or Steam

Select the button (often represented by three dots or a gear icon). Click Repair . Delete the localthumbcache

If you continue to have trouble, it is recommended to ensure all your script mods (such as UI Cheats or MC Command Center) are updated for the newest 2026 patch. If you are still struggling, Share public link

This specific error indicates that The Sims 4 is struggling to read its own setup rules upon launching. Primary causes include:

Sometimes, the startup configuration script itself becomes corrupted during an update or a sudden system shutdown. The EA App and Steam have built-in tools to fix this. For EA App users: Open the EA App and go to your Library. Click the three dots (...) on The Sims 4 tile.