Configuration with Minecraft - Can't start up modded version of Minecraft server

System Information

Field Value
Operating System Linux - Debian GNU/Linux 11 on x86_64
Product AMP ‘Decadeus’ v2.4.6.6 (Mainline)
Virtualization QEMU_KVM
Application Minecraft
Module MinecraftModule
Running in Container No
Current State Failed

Problem Description


Whenever I install FTB Infinity Evolved on my Minecraft instance, it tries to start with vanilla and not modded despite updating server settings.

The console error:


A problem occurred running the Server
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(
at java.base/java.lang.reflect.Method.invoke(
at cpw.mods.fml.relauncher.ServerLaunchWrapper.main(
Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class (jdk.internal.loader.ClassLoaders$AppClassLoader and are in module java.base of loader 'bootstrap')
at net.minecraft.launchwrapper.Launch.<init>(
at net.minecraft.launchwrapper.Launch.main(
... 6 more

Reproduction Steps

  • Create Minecraft Java instance
  • Install FTB Infinity Evolved server
  • Update configuration to use 1.7.10 versions and new jar
  • Start instance
  • Make sure you have Java 8 selected under ConfigurationJava and Memory
  • Delete the world since it’s already generated in vanilla

Then give this a try:

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