PaperMC / PaperMC/Paper

[ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup] Entity uuid already exists:

Open
#14,208 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

scope: performance status: needs triage version: 26.2
Dominant language
Java
Stars
12.7k
Forks
3.5k
Avg merge
3d 13h
Merged PRs (30d)
11

Description

Spark Profile

https://spark.lucko.me/RiEkPDzRTz

Description of issue

Console keeps spitting duplicate UUID errors and I have tried every single fix I could think of. I have no idea what is causing it or why. I have searched across the internet trying to find a fix for this but genuinely just have not been able to.

Full example of the error

[06:35:38 WARN]: [ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup] Entity uuid already exists: 7db31f7c-37d3-4f3d-840d-3cc8e52216f4, mapped to MinecartChest['Minecart with Chest'/9710, uuid='7db31f7c-37d3-4f3d-840d-3cc8e52216f4', l='ServerLevel[world]', x=-741.50, y=-3.50, z=4411.50, cpos=[-47, 275], tl=0, v=false], can't add MinecartChest['Minecart with Chest'/9711, uuid='7db31f7c-37d3-4f3d-840d-3cc8e52216f4', l='ServerLevel[world]', x=-741.50, y=-3.50, z=4411.50, cpos=[-47, 275], tl=0, v=false]

Seems to apply to several entity types but it mostly happens with minecart chests.

Plugin and Datapack List

For Plugins:

AutomaticBroadcast
Bolt
Broadcast
bStats
ChatPing
ChatSentinel
Chunky
CoreProtect
CustomCommands
CustomJoinMessage
DeluxeMenus
DHSupport
DimensionControl
eShulkerBox
Essentials
faststats
GCore
GrimAC
Hat
InteractiveBooks
InventoryRollbackPlus
InvSeePlusPlus
LocatorBarRange
LodServerSupport
Lootin
LuckPerms
NameColor
NBTAPI
PlaceholderAPI
ReportCheckView
SeeU
ServerListPlus
spark
SupremeTags
TAB
Tebex
TogglePvP
TreeFeller
Updater
Vault
voicechat
Votifier
VotingPlugin

For Datapacks
Matcha Flavoured

Server config files
Paste configs or mclo.gs link here!

https://mclo.gs/FSlScdN
https://mclo.gs/SY0MmDq

Paper version

This server is running Paper version 26.2-115-main@de518f7 (2026-08-22T17:16:32Z) (Implementing API version 26.2.build.115-stable)
You are running the latest version
Previous version: 26.2-112-c9e894d (MC: 26.2)

Other

No response

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup entry point and the supplied duplicate-UUID log, then review the linked Spark profile and server configuration files. Reproduce the warning with the reported entity types and plugin context; done means the triggering cause is identified and the duplicate warning is prevented or correctly handled.

Written by the indexing model from the issue text.

Assessment

Tech stack
java
Domain
game-dev
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Active
Clarity
Needs clarification
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.