Startup Issue with Minecraft - Previously working world no longer starts

System Information

Field Value
Operating System Linux - Debian GNU/Linux 13 on x86_64
Product AMP ‘Deimos’ v2.7.2.0 (Mainline)
Virtualization Docker
Application Minecraft
Module MinecraftModule
Running in Container Yes
Current State Failed

Problem Description

Issue

The server was working normally before. Nobody played on it for some time and I did not modify anything. I did not update plugins, change the world, edit configuration files, or install anything.

When I started the server again, it suddenly failed to load the world.

I tested:

  • Paper 26.1.2 and 26.2
  • Java 25
  • Safe mode (–safeMode)
  • Starting with 0 plugins
  • Restoring level.dat from a backup

The problem remains the same.

The server always fails with:

java.lang.IllegalStateException: Overworld settings missing

and

Unable to read or access the world gen settings file.

Reproduction Steps

  • Leave the server offline for some time.
  • Start the server without changing any files, plugins, or configuration.
  • The server fails to start with “Overworld settings missing”.

Check under configuration, updates and make sure it’s using Java 10