System Information
| Field |
Value |
| Operating System |
Linux - Debian GNU/Linux 13 on x86_64 |
| Product |
AMP ‘Deimos’ v2.7.0.0 (Mainline) |
| Virtualization |
Docker |
| Application |
Minecraft |
| Module |
MinecraftModule |
| Running in Container |
Yes |
| Current State |
Failed |
Problem Description
Issue
Error: LinkageError occurred while loading main class net.minecraft.bundler.Main
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
this is the full error message
Reproduction Steps
- started a new minecraft server with java 21 installed
- server unable to start, i researched and download java 25
- i made a new minecraft server with java 25 installed and it gave me the same error message
any help will be very appreciated!!! thanks!
Did you select to use java 25 in the instance after installing it?
could you tell me how to select a java version? I apologize but I don’t know how to. if you are referring to java home, I did change that to java 25.
thanks!! 
Manage the instance, search “java” in the search box
I have been getting the same message after updating the Minecraft Server version using the “Update” button in AMP. If I switch to java 25, the server loads, but I am unable to connect. Mojang recently jumped from 21.xx directly to 26.xx in thier versioning. Not sure if it’s related, but i’m having a heck of a time getting a server up and running since my AMP server updated to 26.1
I found it out!! I tried greelans suggestion but it was already set to java 25, what seemed to work was changing it to java 21, starting the server (the error will happen again) and then switching back to java 25, I think it recognizes java 25 as 21 for some reason. give it a try!!
Can confirm that worked for me as well