| Issue | Probable Cause | Solution | | :--- | :--- | :--- | | | Proxy cannot reach Backend. | Verify Backend server.properties has online-mode=false . Check that the Proxy config.yml points to localhost:25565 . | | Browser Connection Timeout | Firewall blocking Websocket port. | Open port 8081 (TCP) on router and Windows/Linux firewall. | | "Bad Login" | Mojang authentication error. | Ensure the Proxy is in offline mode ( online_mode: false in Bungee config) or configure authentication properly if using a custom auth plugin. | | Version Mismatch | Client version vs Server version. | Ensure the Eaglercraft client is specifically built for 1.12.2 and the backend JAR is strictly 1.12.2. |
: For full control, you can host on your own PC or a VPS using Docker or manual Java setup. 2. Prepare the Core Server how to make a eaglercraft server 1.12.2
You can run both on the same computer, or host the client file on a free static web host (like GitHub Pages) while running the game server on your own machine. | Issue | Probable Cause | Solution |