[Bug]:

[liuxingyu2001-sys]

/mv dumps output

https://mclo.gs/Yw0odoW

Server logs

https://pastes.dev/jUolxebDQw

Server Version

This server is running Purpur version 1.21.10-2535-HEAD@0a2dc04 (1970-01-01T00:00:00Z) (Implementing API version 1.21.10-R0.1-SNAPSHOT)
* You are running the latest version
Previous: 1.21.8-2497-a49cdb9 (MC: 1.21.8)

Bug Description

Multiverse-Core 5.4.0
server is running Purpur version 1.21.10

I cannot create a world or import a world

Steps to reproduce

Bug Report:

Error Message:

[06:59:08] [Server thread/ERROR]: [Multiverse-Core] Failed to create bukkit world: test
java.lang.ClassCastException: class net.minecraft.world.entity.EntityType cannot be cast to class net.minecraft.util.debug.DebugSubscription

Error Analysis:

This is a version incompatibility issue. Detailed analysis:

1. Trigger Command: Player executed /mv create test normal attempting to create a new world

2. Plugin Version: Using multiverse-core-5.4.0.jar

3. Error Type: ClassCastException (Type conversion exception)

   • EntityType cannot be cast to DebugSubscription
   • This occurs during LevelDebugSynchronizers initialization

4. Root Cause:

   • Multiverse-Core 5.4.0 is incompatible with the current server core version
   • Possibly using a newer Paper/Purpur server version, while Multiverse-Core has not been updated to support it yet
   • Newer server versions may have changed internal APIs, causing the plugin to malfunction

Solutions:

1. Update Multiverse-Core Plugin

   • Check for newer versions: https://www.spigotmc.org/resources/390/
   • Download the latest version that supports your server version

2. Check Server Version

   • Verify if your Paper/Purpur version is too recent
   • If using the latest version, you may need to wait for Multiverse-Core to update

3. Temporary Workaround

   • Use Bukkit native command to create world: /mv create test normal -t FLAT or other world types
   • Or downgrade server version to one supported by Multiverse-Core

Recommendation:
First check your server version, then download the corresponding version of Multiverse-Core plugin.

Agreements

• I have searched for and ensured there isn't already an open or resolved issue(s) regarding this.
• I was able to reproduce my issue on a freshly setup and up-to-date server with the latest version of Multiverse plugins with no other plugins and with no kinds of other server or client mods.

[benwoo1110]

Did you reproduce the issue with only Multiverse plugins installed?