1.) If you are using a PS4 or PS5 controller, you have to use the DS4Windows Program.[github.com] In order to set that up, go to the settings tab in DS4Windows, "Controller/Driver Setup", click "Install ViGEmBus Driver", then restart your computer.

2.) Download the latest Nucleus Coop Program[github.com] to play split-screen. Password is "nucleus" . (OPTIONAL: Use the 7zip[www.7-zip.org] program to extract, if needed.)

3.) Extract and place the NucleusCoop folder you downloaded anywhere. (I placed mine on my desktop.)

4.) Place the NucleusCoop folder into the root of your hard drive.

5.) Make sure Halo the Master Chief collection is located on the same hard drive as the "Nucleus Coop" folder (in this example, it is C:/). If not, put them on the same hard drive. But do not put the "Nucleus Coop" folder into your Master Chief collection directory.

6.) This step is optional. Right click on the program, "NucleusCoop.exe", go to properties, go to the "compatibility" section at the top, check the box marked "Run this program as an administrator". Press "OK".

1.) Do the prerequisites.

2.) To use workshop mods, create a "ModManifest.txt" file in "C:Users<Your Username>AppDataLocalLowMCCConfig", in it; paste the full workshop directory (usually is in the same drive where the game is installed, "steamsteamappsworkshop976730").

3.) Start "NucleusCoop.exe".

4.) Click on the "Download Game Handler" button in the top middle.

5.) Search for Halo. Find Halo the Master Chief Collection. Click on it, then click "Download".

6.) It will finish, then pop up with a dialogue. Click yes, then find your Halo executable located in "your game directory"/MCC/Binaries/Win64/MCC-Win64-Shipping.exe. (You can find "your game directory" by right clicking on the game, then going to manage, then click on browse local files.)

7.) Set up your controllers by clicking on the small box below the keyboard icon. Drag your controllers into your set up configuration. If you have a multi-monitor setup, you can also setup each screen for split-screen here!

8.) Hit the right arrow button in the top right, below "Mod version", then the "Play" button.

9.) Lastly, to connect the instances, go to the Settings, in the Network tab swap from Xbox Live to LAN on all instances, save the changes and go back to the menu, open the roster by pressing X or hovering over it and join with each instance to Player 1's lobby.

10.) (OPTIONAL STEP: This will reduce startup time) Exit the Nucleus Coop application. Inside the "Nucleus Coop" folder, go into "handlers", right click on "Halo The Master Chief Collection", click "edit", do ctrl+F, find 35, change 30 to 3, and save and exit. Reopen the Nucleus Coop application.

11.) (OPTIONAL STEP: To further reduce startup time) Download the skip intro mod[www.nexusmods.com], and place it in Halo The Master Chief CollectionMCCContentMovies, and replace the old file.

"Could not find a part of the path 'f....commonhalo the master chief collectionhalo1originalbuildshaders'. ".

"Halo fatal error" or "Halo error static".

[Type]
DirectoryNotFoundException

[Message]
Could not find a part of the path
'Y:\SteamLibrary\steamapps\common\Halo The Master Chief Collection\NucleusCoop\content\Halo
MCC\Instance0\NucleusCoop\handlers\Halo The Master Chief Collection\steam_appid.txt'.

First, verify the integrity of your game file. Make sure your game is on the same hard drive as your Nucleus Coop folder. If those two things didn't work, try moving your game to your C: hard drive.

"Could not find a part of the path...'shaders_2_cache\prebuild'."

"Missing Content" error.

1) Download the latest version of the Halo the Master Chief Collection handler.

2) Then If you are still experiencing the missing content with this latest version, set these lines to false in the handler:
Game.UseNucleusEnvironment =
Game.GoldbergNoLocalSave =

Reinstall the handler by deleting the Halo handler and redownloading it. And verify the integrity of your game.

Nucleus Coop log:
[Message]
Unknown error code (-1073741275): The given process does not exist. (Code: 87)

[Stacktrace]
at EasyHook.NativeAPI.Force(Int32 InErrorCode)...

Frozen on "Hardlinking games files..."

Make sure that you are on a computer with all admin privileges (thanks to TeeWin for this fix).

You can not invite another person. When you try to invite someone, the mouse is stuck in a steam overlay window

One controller controls multiple people or one controller does not function properly.

Reinstall the latest handler and verify the integrity of your game. Also, exit Steam, and play without Steam.

Frozen on the "Pausing for 30 seconds" window or the "Creating raw input" window.

Put the "Nucleus Coop" folder you created into a different location, such as C:/Program Files (x86). Also disable the "Show Status Window" in Nucleus Settings. This is a new feature introduced in the last version but is causing issues for some users.

Pop window that says "ERROR: Exception in ResetWindows for...".

Go to the "Halo The Master Chief Collection" handler, and increase the pause time from 3 to 4, 5, 6, etc. Also disable the "Show Status Window" in Nucleus Settings. This is a new feature introduced in the last version but is causing issues for some users.

Can not find the other player in roster

Are you on LAN in the in-game, network settings? Do you have VPN. If so, turn that off.

Keyboard or mouse is not working

Did you select both the mouse AND keyboard, when selecting controllers in the Nucleus Co-op menu? You need to press a button on the keyboard and mouse you want to use for them to show up. Also, try HOLDING End and moving the mouse once prompted.

Your computer freezes in the middle of while you are playing.