How to install a Minecraft Java version with McJars¶

McJars is the panel's built-in installer for Java server software. Use it to install a fresh server or to change the version of an existing one.

Before you start¶

• Make sure your server uses Server Java.
• If you are changing software or version on an existing server, stop the server first and back up your data.
• Do not downgrade an existing world to an older Minecraft version, and verify that your plugins and mods are compatible with the software or version you are installing.
• Prepare the Minecraft version you want to install. This guide uses 1.21 as an example.

Installation steps¶

1. Open https://panel.nexuscloud.id/ and select your server.
2. On mobile, tap the ☰ menu and scroll to McJars.
3. Open the McJars menu.
4. Set Software Type to the Java server software you want to install, for example Java Paper.
5. Pick the Minecraft version you want to install, for example 1.21.
6. Click Start Download and wait for the installation to finish.
7. Open the Startup menu and set the Docker Image to match the selected Minecraft version. For Java Paper on Minecraft 1.21, use Java 21 Temurin; for other software, follow that software's runtime requirements in the Java version guide.
8. Open the Console menu and start the server.
9. Wait until the console shows the server is ready to accept connections.

Troubleshooting¶

Server fails to start after installing¶

• Check that Software Type matches the Java server software you want to install. A mismatch means the wrong files were downloaded.
• Check that the Docker Image in Startup matches the software and Minecraft version you selected. For Java Paper on Minecraft 1.21, that is Java 21 Temurin.

Cheers, Team NexusCloud