RED4ext Error 1813 Cyberpunk 2077 | How to Fix

A “RED4ext error 1813” is a specific issue that occurs in the modding community for the game Cyberpunk 2077. It’s not a generic error and almost always points to a mod-related problem, particularly after a game update.

The error message often comes with a note about a resource type not being found or a hash failing to resolve, which means a mod is trying to load a file or access a memory address that no longer exists in the game’s updated version.

Primary Cause: Outdated Mods

The most common reason for a RED4ext error 1813 is that a core mod or a mod that depends on RED4ext is outdated after a new Cyberpunk 2077 patch. When the game updates, the underlying game code and addresses can change, breaking mods that were built for the previous version.

How to Troubleshoot and Fix It

Follow these steps in order, as they progress from the simplest and most likely solutions to more drastic measures.

1. Update All Core Mods:

   • This is the most important step. Check for updates for all of your “foundational” mods, as they are almost always the cause of this error.
   • Essential mods to check:
     • RED4ext (the mod that’s giving you the error)
     • Cyber Engine Tweaks
     • redscript
     • ArchiveXL
     • TweakXL
     • Codeware
   • Check the Nexus Mods pages for these mods. The mod authors are usually very quick to release new, compatible versions after a game update.

2. Verify Your Game Files:

   • If updating the mods doesn’t work, a simple way to rule out corrupted files is to verify the integrity of your game files.
   • On Steam: Right-click Cyberpunk 2077 in your library > Properties > Installed Files > Verify integrity of game files.
   • On GOG: Click Cyberpunk 2077 > Manage Installation > Verify / Repair.
   • This process will scan your game’s files and replace any that are missing or corrupted. It’s a good way to get back to a clean state.

3. Perform a Clean Reinstallation of All Mods:

   • This is often the most effective solution for persistent issues.
   • Disable all your mods in your mod manager (like Vortex) or, for a more thorough clean, manually delete all mod files from your game directory.
   • Verify your game files again to ensure a completely clean, vanilla installation.
   • Reinstall all of your mods one by one, making sure you are downloading the latest versions. It’s best to start with the core mods (RED4ext, CET, etc.) and then add your other mods back in.

4. Check for Mod Conflicts:

   • If the error only appears after you’ve installed a specific mod, that mod is likely the culprit. It may be outdated or incompatible with another mod you have installed.
   • Try running the game with only your core mods to see if it works. If it does, you can then add other mods back in small batches to find the one causing the conflict.

5. Check the RED4ext Log File:

   • Sometimes, the error message in the game launcher is generic, but the RED4ext log file can provide more specific details.
   • Look for a file named red4ext.log in the Cyberpunk 2077/red4ext/logs folder.
   • Open this file and look for any errors or warnings. This can often point directly to the mod that is causing the problem.

Also Read : YouTube Music Revanced Error 400

In summary, a “RED4ext error 1813” is a clear sign that a mod is out of date. By systematically updating your core mods and then other mods, or by performing a clean reinstall, you can almost always resolve the issue.