Java Version Requirements per Minecraft Version
Which JDK each Minecraft build hard-requires, and how to switch it on Endercloud.
The Hard Rules
Modern Minecraft is sensitive to the JVM. Wrong Java version = server refuses to boot or crashes on the first chunk load.
- MC 1.8 ā 1.11 ā Java 8
- MC 1.12 ā 1.16 ā Java 8 (Forge 1.12.2 is strictly Java 8)
- MC 1.17 ā Java 16
- MC 1.18+ ā Java 17 (hard dependency, no fallback)
- MC 1.20.5+ ā Java 21
Switch Java On Endercloud
- 1Panel ā your server ā Startup
- 2Find Docker Image / Java Version
- 3Select the version your JAR needs
- 4Restart the server
If you upgrade your JAR but forget to bump Java, the console prints UnsupportedClassVersionError on startup. Bump Java, restart.
Aikar Flags
Once you're on the right version, paste Aikar's flags into the startup parameters. They tune G1GC for Minecraft's allocation pattern. Search "Aikar flags generator", paste in your RAM and the version, copy the output.
Need More Help?
Console showing UnsupportedClassVersionError or Unrecognized VM option? Open a ticket and we'll match the JVM.
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