MO2 (Mod Organizer 2)

How to use MO2 - it's that simple

Summary

Last documented update: May 19 2025 by MyNameIsSpirits

MO2 (Mod Organizer 2, Nexus | Github) is a free, widely-used mod manager, especially popular for Bethesda games. It also fully supports Cyberpunk 2077.

Using MO2 keeps your base game directory untouched and allows for easy mod installation, uninstallation, and updating. Additionally, you can create different profiles for mod configurations.

If you need further help with MO2 beyond this guide, feel free to ask for assistance on their official Discord server.

Before we start...

MO2 will not play nice with manually installed mods - remove them.

MO2 keeps all your mods in a location separate from Cyberpunk's base game directory. When you launch Cyberpunk through MO2, it will load mods from both MO2 and the game folders.

It's best to let MO2 handle all of your mods and leave the base game directory clean.

But I have so many mods to uninstall!

You don't need to manually delete all of your mods, nor should you reinstall the entire game.

We have a handy mod remover script (courtesy of our dear manavortex) that will automatically do it for you.

After running it and validating your files, you will have a 100% clean installation of the game and a backup folder of the mods it removed, in case you change your mind about MO2 and want those mods back.

TL;DR: Don't reinstall the game. You'll be wasting your time. Use the mod remover.

Download and Install MO2

1. Download MO2 from either Nexus Mods (yes, Skyrim Nexus) or GitHub

2. Install MO2:

   • When installing, choose either the Global Instance option (recommended for multiple games)...

   • ...or choose Portable Instance if you want a separate installation of MO2 for each game.

Do not install MO2 inside Cyberpunk's directory! This has been confirmed to cause issues.

Setting Up the Game

1. Launch MO2.

2. Create a new instance:

   • Browse to the Cyberpunk 2077 installation folder to create the new game instance.

3. Customize your Profile Settings (Optional):

   • These can be left unchecked unless you need profile-specific INI files, save games, or automatic archive invalidation.

   • You can change these settings later as needed.

Installing CET and Red4Ext (the script extenders)

You can either install these mods manually, or install Zash's plugin update (see ) Script extenders: plugin installation guide

Script extenders: Manual install

If you would rather use the (experimental) plugin, read Script extenders: plugin installation guideinstead.

1. Download the mod from Nexus

2. Open the downloaded .zip file by double-clicking it

3. Drag and drop everything inside the folder directly into The Cyberpunk 2077 Game Directory

4. You're done

Script extenders: plugin installation guide

If you would rather install the mods by hand, read Script extenders: Manual installinstead.

There is a plugin for MO2 that will allow you to install CET and RED4ext through MO2. This is nice if you prefer to keep all of your mods within MO2's mod list, but it is an optional process.

If you don't care about having CET and RED4ext installed in MO2, then I would recommend you to install them manually as detailed above. Otherwise, read on.

I'm going to stress this as hard as I can: this plugin is not part of the main MO2 build and is therefore prone to bugs. I haven't had any issues with it so far, and I was able to guide someone who'd never even heard of MO2 previously, and they also have not experienced any issues.

With that said, there is always a possibility that something simply doesn't work as expected. If you're absolutely, totally, undoubtedly 100% sure that you followed the below steps correctly and it still doesn't work, I would advise you to visit the official MO2 Discord server linked at the top of this guide and seek help there.

Installing the plugin (must read!)

1. Head over to the GitHub repository and download the file game_cyberpunk2077.py by clicking on the top-right three-dot menu, and clicking "Download."

2. Place this file into basic_games/games which is located in the MO2 plugin folder. No need to go diving through all your folders to find it, you can find it easily:

   1. Navigate to Show Open Folders menu... on the main MO2 screen.

      

      Show Open Folders menu
   2. Click on Open MO2 Plugins folder.

      

      Open MO2 Plugins
   3. This will open the plugins folder in Windows Explorer. From here, go into the folder called basic_games, and then into games.

   4. This is where you'll drop the file you downloaded from GitHub. However, there will already be a file in here called game_cyberpunk2077.py which you should back up in case something goes wrong (simply copying it to your desktop will suffice, as long as you remember where you put it).

   5. After you've backed up the original file, now you can drop the file you downloaded from GitHub into this folder. Replace the original file if it asks you to (again, back it up first!).

3. At this point you have installed the plugin, but we're not done yet. Next you should install CET and RED4ext through MO2 (see Installing Mods from Nexus below), replacing any previous installations of those mods if you had any.

4. Make sure your Overwrite folder is empty, backing up any files in there if you need.

   1. The Overwrite folder is where MO2 puts files generated by your mods while you're playing the game. For the sake of setting up our plugin, it's better to make sure it's empty to avoid potential file conflicts.

   2. The Overwrite is found at the very bottom of your installed mod list (not the Downloads tab). Double-click on Overwrite and delete everything in the window that pops up. If there's nothing in there, move onto the next step.

5. Make sure Root Builder is disabled with the following steps.

   1. Go to Settings.

      

      Settings
   2. Head to the Plugins section.

   3. Search for Root Builder and make sure the "Enabled" checkbox is not checked. If Root Builder doesn't show up, that means you didn't have it installed in the first place. That's okay! You don't need to do anything more.

   
6. If you have CET and RED4ext installed manually, you should remove them from Cyberpunk's game folders. The easiest way to do this is via mod remover.

7. After you've done all of this, close and re-open MO2. If you've followed all of these steps correctly, you should receive a pop-up which you should say yes to.

8. Launch the game. If everything is done correctly, CET should open immediately and ask you to set a keybind. You've done it!

Installing Mods from Nexus

1. Go to the Nexus Mods website for Cyberpunk 2077 mods.

2. Download mods via the "Mod Manager Download" button. MO2 will start to automatically download the mod.

3. In MO2, open the Downloads tab and double-click the mod to install it.

4. After installation, ensure the mod is enabled by checking it in the Plugins list or the Installed Mods section.

Adding Mods from Other Sources

If you have mods from external sources:

• Download the mod and move it to the Downloads folder by using the file folder dropdown in MO2 ("Open Downloads folder").

• Alternatively, drag and drop the mod into the Downloads tab within MO2.

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Launching the Game

When using MO2 as a mod manager, you always have to launch the game through MO2.

1. Always Launch the Game through MO2:

   • If you're using MO2 as your mod manager, make sure to run Cyberpunk 2077 via MO2. Your mods will not be loaded otherwise.

   • Steam will still track your playtime and achievements.

2. Run the Game:

   • After setting up all your desired mods, click Run in MO2 to launch Cyberpunk 2077.

Tips and Best Practices

• Stay up to date with the latest versions of both MO2 and the mods for the best experience and compatibility.

Troubleshooting

Some mods aren't working!

• If you aren't using the updated plugin, make sure that CET and RED4ext are installed manually (check Installing CET and Red4Ext (the script extenders))

• If you are using the updated plugin and you're getting REDscript errors on startup, make sure you've restarted MO2 after updating the plugin.

• Make sure that your MO2 instance is not directly in the The Cyberpunk 2077 Game Directory. This has been confirmed to cause problems and is a non-optional step.