Startup Issue with Minecraft - no key seed or dimensions in MapLike

System Information

Field Value
Operating System Linux - Debian GNU/Linux 13 on x86_64
Product AMP ‘Proteus’ v2.8.0.4 (Mainline)
Virtualization Podman
Application Minecraft
Module MinecraftModule
Running in Container Yes
Current State Failed

Problem Description

IssueservicesHost=‘https://api.minecraftservices.com’, name=‘PROD’

[00:53:05] [main/ERROR]: WorldGenSettings: No key dimensions in MapLike[{}]; No key seed in MapLike[{}]
[00:53:05] [main/WARN]: Failed to load datapacks, can’t proceed with server load. You can either fix your datapacks or reset to vanilla with --safeMode
java.util.concurrent.ExecutionException: java.lang.RuntimeException: No key dimensions in MapLike[{}]; No key seed in MapLike[{}]
at java.util.concurrent.CompletableFuture.wrapInExecutionException(CompletableFuture.java:345) ~[?:?]
at java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:440) ~[?:?]
at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:2094) ~[?:?]
at net.minecraft.server.Main.main(Main.java:209) ~[server-intermediary.jar:?]
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:514) ~[fabric-loader-0.19.3.jar:?]
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:72) ~[fabric-loader-0.19.3.jar:?]
at net.fabricmc.loader.impl.launch.knot.KnotServer.main(KnotServer.java:23) ~[fabric-loader-0.19.3.jar:?]
at net.fabricmc.loader.impl.launch.server.FabricServerLauncher.main(FabricServerLauncher.java:69) ~[fabric-loader-0.19.3.jar:?]
at net.fabricmc.installer.ServerLauncher.main(ServerLauncher.java:69) ~[fabric.jar:1.1.2]
Caused by: java.lang.RuntimeException: No key dimensions in MapLike[{}]; No key seed in MapLike[{}]
at com.mojang.serialization.DataResult.lambda$getOrThrow$5(DataResult.java:101) ~[datafixerupper-6.0.8.jar:?]
at com.mojang.datafixers.util.Either$Right.map(Either.java:99) ~[datafixerupper-6.0.8.jar:?]
at com.mojang.serialization.DataResult.getOrThrow(DataResult.java:93) ~[datafixerupper-6.0.8.jar:?]
at net.minecraft.class_32.method_29582(class_32.java:276) ~[server-intermediary.jar:?]
at net.minecraft.class_32.method_26998(class_32.java:234) ~[server-intermediary.jar:?]
at net.minecraft.class_32$class_5143.method_27013(class_32.java:433) ~[server-intermediary.jar:?]
at net.minecraft.server.Main.method_43613(Main.java:167) ~[server-intermediary.jar:?]
at net.minecraft.class_7237.method_42098(class_7237.java:42) ~[server-intermediary.jar:?]
at net.minecraft.server.Main.method_43612(Main.java:162) ~[server-intermediary.jar:?]
at net.minecraft.class_156.method_43498(class_156.java:944) ~[server-intermediary.jar:?]
at net.minecraft.class_156.method_43499(class_156.java:938) ~[server-intermediary.jar:?]
at net.minecraft.server.Main.main(Main.java:160) ~[server-intermediary.jar:?]
… 5 more

Reproduction Steps

  • make instance
  • start it as a test and then turn it off
  • change to fabric 1.20.1

This commonly happens when you try to launch a vanilla server on a modded world or vice versa.

  1. Can you please include more information about your goal?
  2. When switching to the Fabric server type, did you press “Download/Update” afterward?
  3. Is this a fresh world/instance or did you import a world, for instance?