How to Downgrade Fallout 4 Anniversary Edition

The Fallout 4 Anniversary Edition update broke many mods and caused widespread crashes. This guide will help you roll back to the previous version in under 5 minutes.

Why Downgrade?

The AE update (version 1.10.984+) introduced several breaking changes:

Script Extender (F4SE) incompatibility - Most SKSE-dependent mods stopped working
Save file corruption - Some players reported corrupted saves after the update
Performance issues - FPS drops and stuttering increased for many users
Mod conflicts - Over 150+ Creation Club items caused compatibility issues

Prerequisites

Before you start, make sure you have:

Steam installed on your PC
At least 30GB of free disk space
A backup of your save files (located in Documents/My Games/Fallout4/Saves)
Admin access to your computer

Method 1: Steam Console Method (Recommended)

This is the fastest and most reliable method.

Step 1: Open Steam Console

Open your web browser
Navigate to: steam://nav/console/
This will open Steam with the console active

Step 2: Download Previous Version

In the Steam console, type:

``` download_depot 377160 377161 7497069378349273908 ```

Explanation:

377160 - Fallout 4 App ID
377161 - Depot ID for the base game
7497069378349273908 - Manifest ID for pre-AE version

Step 3: Locate Downloaded Files

The files will be downloaded to: ``` Steam/steamapps/content/app_377160/depot_377161/ ```

Step 4: Replace Game Files

Navigate to your Fallout 4 installation folder
Back up the current Fallout4.exe (rename it to Fallout4.exe.bak)
Copy the downloaded files to your game directory
Overwrite when prompted

Step 5: Disable Auto-Updates

Right-click Fallout 4 in Steam Library
Select Properties
Go to Updates tab
Set Automatic updates to "Only update this game when I launch it"
Important: Always launch the game through F4SE or your mod manager, never through Steam directly

Method 2: Using Fallout 4 Downgrader Tool

If you prefer a GUI tool:

Download Fallout 4 Downgrader from Nexus Mods
Run the tool as Administrator
Select your Fallout 4 installation directory
Choose "Pre-Anniversary Edition" from the version dropdown
Click "Downgrade" and wait for the process to complete

Post-Downgrade Steps

After downgrading, follow these steps to ensure everything works:

1. Reinstall F4SE

Download the latest F4SE compatible with your downgraded version from f4se.silverlock.org

2. Update Your Mods

Some mods may need updates even for the pre-AE version. Check Nexus Mods for:

Unofficial Fallout 4 Patch
Buffout 4
High FPS Physics Fix

3. Verify Your Save Files

Launch the game through F4SE
Load your most recent save
Play for 10-15 minutes to ensure stability
Make a new manual save as a checkpoint

Common Issues and Fixes

"Missing MSVCP140.dll" Error

Solution: Install Visual C++ Redistributables from Microsoft's website.

Game Won't Launch After Downgrade

Solution:

Verify game files through Steam
Delete Fallout4Prefs.ini from Documents/My Games/Fallout4
Launch the game without mods first

Mods Still Not Working

Solution:

Check if F4SE is correctly installed
Verify F4SE version matches your game version
Reinstall problematic mods one by one

Preventing Future Issues

To avoid forced updates:

Never launch through Steam - Always use F4SE or mod manager
Keep a backup - Save a copy of your working game folder
Stay informed - Follow r/FalloutMods for update news
Use Mod Organizer 2 - It isolates mods from game files

Conclusion

Downgrading Fallout 4 is straightforward with the Steam console method. The entire process takes less than 10 minutes, and you'll have your mods working again.

Remember to disable auto-updates and always launch through F4SE to prevent Steam from forcing the Anniversary Edition update again.

Additional Resources

Last Updated: November 13, 2025 Tested On: Windows 10/11, Steam version