Fix Halo MCC Campaign Co-op Disconnects on Linux
Game: Halo: The Master Chief Collection
Platform: Steam / Linux
Working Proton Version: 7.0-6
The Problem
While playing Halo: Reach campaign co-op between two Linux computers, both players were disconnected and returned to the lobby approximately 30 seconds after starting.
Both computers were using Proton Experimental.
The Fix
Switch both computers to Proton 7.0-6.
- Open Steam Library.
- Right-click Halo: The Master Chief Collection → Properties.
- Select Compatibility.
- Enable Force the use of a specific Steam Play compatibility tool.
- Select Proton 7.0-6.
- Repeat on the other computer and restart the game.
Results
| Proton Version | Result |
|---|---|
| Proton Experimental | Disconnected after ~30 seconds |
| Proton 7.0-6 | Co-op worked |
Conclusion: Proton 7.0-6 resolved our Halo: Reach campaign co-op disconnections on Linux. No additional configuration or launch options were required.