Upload a Custom JAR File to Your Minecraft Server

Published 9 June 2026 · By Host Havoc Technical Support Team

Host Havoc lets you run any custom Minecraft server JAR on your server. You need to rename the JAR to the correct filename for your Java version and select the matching option in the Minecraft panel.

Before starting, connect to your server via FTP.

Version and filename reference table

Minecraft versionJava versionRequired filenameMulticraft JAR option
1.1 - 1.11.2Java 8custom-1112below.jarCustom Jar File (MC 1.11.2 and Below)
1.12.X - 1.16.5Java 8custom.jarCustom Jar File (MC 1.12 to 1.16x)
1.17 - 1.17.1Java 16custom-java-16.jarCustom JAR File for Java 16
1.18 - 1.20.4Java 17custom-java-17.jarCustom JAR File (Minecraft 1.18.X and above)
1.20.5 - 1.20.XJava 21custom-java-21.jarCustom JAR File (Minecraft 1.20.5 and above)
1.26+Java 25custom-java-25.jarCustom JAR File (Minecraft 1.26 and above)

Steps

  1. Download the JAR file you want to run (for example, a Paper, Purpur, or other server JAR).
  2. Rename the JAR to the filename shown in the table above for your version.
  3. Connect via FTP and upload the renamed JAR to the root (base) directory of your server.
  4. Log in to the Minecraft panel and open your server settings.
  5. Find the JAR File setting and select the option from the table that matches your version.
  6. Click Save and restart your server.

Note: For Minecraft 1.17 and newer, selecting the wrong JAR option will cause the server to fail to start because each option runs a different Java version. Always match the Multicraft option to your Minecraft version using the table above.

Troubleshooting

ProblemSolution
Server fails to startConfirm the JAR filename matches the table exactly, including the .jar extension.
Wrong Java version errorRe-check the table and update the JAR File selection in Multicraft.
File not found errorEnsure you uploaded the JAR to the root directory, not a subdirectory.