How to Install Build 42 Unstable on Your Project Zomboid Server

Published June 9, 2026 · By Host Havoc Technical Support Team

The unstable branch lets you access early Build 42 features on your server before the stable release. This process runs a repair and file validation to ensure a clean switch. After switching, you will also need to set your server admin password if it has not been configured. See change admin password if needed.

Switch to the unstable branch

  1. Log in to the Game Control Panel and navigate to your server.
  2. Stop the server.
  3. Click the ...More button and run the Repair option.
  4. Once the repair completes, click ...More again and run the Validate Server Files option.
  5. In the branch settings, select Unstable as the branch.
  6. Set your Server Admin Password.
  7. Start your server.