System Information
| Field | Value |
|---|---|
| Operating System | Linux - Debian GNU/Linux 12 on x86_64 |
| Product | AMP ‘Phobos’ v2.6.4.2 (Mainline) |
| Virtualization | None |
| Application | Minecraft |
| Module | MinecraftModule |
| Running in Container | No |
| Current State | Failed |
Problem Description
Issue
When starting the Fabric server in AMP, it throws:
java.lang.UnsupportedClassVersionError: net/minecraft/bundler/Main has been compiled by a more recent version of the Java Runtime (class file version 69.0), this version of the Java Runtime only recognizes class file versions up to 65.0.
Java 21 is installed and selected in AMP, but the server still fails to recognize it. Startup fails immediately, preventing server access
Reproduction Steps
- Installed AMP and created a Fabric Minecraft server instance
- Set Java version to Temurin 21 (system default) and memory limits
- Attempted to start the server via AMP; received UnsupportedClassVersionError