ArrayIndexOutOfBoundsException: Index 24 out of bounds for length 24, followed chunk data be lost

[Pen92he]

Stack trace

[20:20:32] [Paper Common Worker #2/ERROR]: [ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask] Failed to parse chunk data for task: GenericDataLoadTask{class: ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask$ChunkDataLoadTask, world: world, chunk: (23,419), hashcode: 1798463854, priority: NORMAL, type: CHUNK_DATA}, chunk data will be lost
java.lang.ArrayIndexOutOfBoundsException: Index 24 out of bounds for length 24
at net.minecraft.world.level.chunk.ChunkAccess.getOrCreateOffsetList(ChunkAccess.java:461) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at net.minecraft.world.level.chunk.ChunkAccess.addPackedPostProcess(ChunkAccess.java:380) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at net.minecraft.world.level.chunk.storage.SerializableChunkData.read(SerializableChunkData.java:419) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask$ChunkDataLoadTask.runOffMain(ChunkLoadTask.java:355) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.GenericDataLoadTask$ProcessOffMainTask.run(GenericDataLoadTask.java:311) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at ca.spottedleaf.concurrentutil.executor.thread.BalancedPrioritisedThreadPool$OrderedStreamGroup$Queue.lambda$createTask$0(BalancedPrioritisedThreadPool.java:429) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.queue.PrioritisedTaskQueue$PrioritisedQueuedTask.execute(PrioritisedTaskQueue.java:345) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.BalancedPrioritisedThreadPool$OrderedStreamGroup.executeTask(BalancedPrioritisedThreadPool.java:309) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.BalancedPrioritisedThreadPool$WorkerThread.pollTasks(BalancedPrioritisedThreadPool.java:592) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.mainLoop(PrioritisedQueueExecutorThread.java:57) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.doRun(PrioritisedQueueExecutorThread.java:122) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.run(PrioritisedQueueExecutorThread.java:49) ~[concurrentutil-0.0.7.jar:?]
[20:20:32] [Paper Common Worker #2/WARN]: Ignoring heightmap data for chunk [-5, 419], size does not match; expected: 37, got: 43
[20:20:32] [Paper Common Worker #2/WARN]: Ignoring heightmap data for chunk [-5, 419], size does not match; expected: 37, got: 43
[20:20:32] [Paper Common Worker #2/WARN]: Ignoring heightmap data for chunk [-5, 419], size does not match; expected: 37, got: 43
[20:20:32] [Paper Common Worker #2/WARN]: Ignoring heightmap data for chunk [-5, 419], size does not match; expected: 37, got: 43
[20:20:32] [Paper Common Worker #2/ERROR]: [ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask] Failed to parse chunk data for task: GenericDataLoadTask{class: ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask$ChunkDataLoadTask, world: world, chunk: (-5,419), hashcode: 1436260670, priority: NORMAL, type: CHUNK_DATA}, chunk data will be lost
java.lang.ArrayIndexOutOfBoundsException: Index 24 out of bounds for length 24
at net.minecraft.world.level.chunk.ChunkAccess.getOrCreateOffsetList(ChunkAccess.java:461) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at net.minecraft.world.level.chunk.ChunkAccess.addPackedPostProcess(ChunkAccess.java:380) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at net.minecraft.world.level.chunk.storage.SerializableChunkData.read(SerializableChunkData.java:419) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask$ChunkDataLoadTask.runOffMain(ChunkLoadTask.java:355) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.GenericDataLoadTask$ProcessOffMainTask.run(GenericDataLoadTask.java:311) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at ca.spottedleaf.concurrentutil.executor.thread.BalancedPrioritisedThreadPool$OrderedStreamGroup$Queue.lambda$createTask$0(BalancedPrioritisedThreadPool.java:429) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.queue.PrioritisedTaskQueue$PrioritisedQueuedTask.execute(PrioritisedTaskQueue.java:345) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.BalancedPrioritisedThreadPool$OrderedStreamGroup.executeTask(BalancedPrioritisedThreadPool.java:309) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.BalancedPrioritisedThreadPool$WorkerThread.pollTasks(BalancedPrioritisedThreadPool.java:592) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.mainLoop(PrioritisedQueueExecutorThread.java:57) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.doRun(PrioritisedQueueExecutorThread.java:122) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.run(PrioritisedQueueExecutorThread.java:49) ~[concurrentutil-0.0.7.jar:?]
[20:20:32] [Paper Common Worker #4/WARN]: Ignoring heightmap data for chunk [26, 419], size does not match; expected: 37, got: 43
[20:20:32] [Paper Common Worker #4/WARN]: Ignoring heightmap data for chunk [26, 419], size does not match; expected: 37, got: 43
[20:20:32] [Paper Common Worker #4/WARN]: Ignoring heightmap data for chunk [26, 419], size does not match; expected: 37, got: 43
[20:20:32] [Paper Common Worker #4/WARN]: Ignoring heightmap data for chunk [26, 419], size does not match; expected: 37, got: 43
[20:20:32] [Paper Common Worker #4/ERROR]: [ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask] Failed to parse chunk data for task: GenericDataLoadTask{class: ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask$ChunkDataLoadTask, world: world, chunk: (26,419), hashcode: 588050447, priority: NORMAL, type: CHUNK_DATA}, chunk data will be lost
java.lang.ArrayIndexOutOfBoundsException: Index 24 out of bounds for length 24
at net.minecraft.world.level.chunk.ChunkAccess.getOrCreateOffsetList(ChunkAccess.java:461) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at net.minecraft.world.level.chunk.ChunkAccess.addPackedPostProcess(ChunkAccess.java:380) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at net.minecraft.world.level.chunk.storage.SerializableChunkData.read(SerializableChunkData.java:419) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask$ChunkDataLoadTask.runOffMain(ChunkLoadTask.java:355) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.GenericDataLoadTask$ProcessOffMainTask.run(GenericDataLoadTask.java:311) ~[paper-1.21.10.jar:1.21.10-129-3e25649]
at ca.spottedleaf.concurrentutil.executor.thread.BalancedPrioritisedThreadPool$OrderedStreamGroup$Queue.lambda$createTask$0(BalancedPrioritisedThreadPool.java:429) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.queue.PrioritisedTaskQueue$PrioritisedQueuedTask.execute(PrioritisedTaskQueue.java:345) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.BalancedPrioritisedThreadPool$OrderedStreamGroup.executeTask(BalancedPrioritisedThreadPool.java:309) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.BalancedPrioritisedThreadPool$WorkerThread.pollTasks(BalancedPrioritisedThreadPool.java:592) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.mainLoop(PrioritisedQueueExecutorThread.java:57) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.doRun(PrioritisedQueueExecutorThread.java:122) ~[concurrentutil-0.0.7.jar:?]
at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.run(PrioritisedQueueExecutorThread.java:49) ~[concurrentutil-0.0.7.jar:?]

### Plugin and Datapack List

Server Plugins (59):
*AntiAttack, AntiSeedCracker, AntiSpawner, AstraRating, BetterRTP, Blackjack, BustaMine, CatSeedLogin, Citizens, CMILib
 ColorGradient, CompanionsPlus, CopsAndCrims, CoreProtect, DeathMessages, DelayedCommand, DreamCleaner, Essentials, EssentialsChat, EssentialsProtect
EssentialsSpawn, GlobalMarketPlus, GrimAC, GSit, ILoreEdit, Images, Ip2region, JulySafe, LiteSignIn, LuckPerms
 mcMMO, McMmoView, MiniMOTD, Multiverse-Core, NeonRewardPlus, NoCommand, PlaceholderAPI, PlayerGuild, PlayerMenu, PlayerParticles
 PlayerPoints, PlayerSafe, PlayerTask, PlayerTitle, PlayerWarp, *PlayMoney, PointLogger, ProtocolLib, QuickShop-Hikari, RandomShop
 Residence, Sentinel, SkinsRestorer, SpawnLimit, TAB, Vault, VirtualBooks, VoidFramework-Bukkit, WorldEdit

There are 4 data pack(s) enabled: [vanilla (built-in)], [file/bukkit (world)], [paper (built-in)], [file/iris (world)]

### Actions to reproduce (if known)

<img width="2215" height="1273" alt="Image" src="https://github.com/user-attachments/assets/774d6221-44d7-4811-a6ec-7a8730c3404a" />


The server was upgraded from version 1.20.4 to 1.21.10, and the map archive was damaged after entering the server. The specific manifestation was the lack of buildings, and the missing parts generated new terrain and blocks

### Paper version

This server is running Paper version 1.21.10-129-ver/1.21.10@3e25649 (2025-12-19T23:34:30Z) (Implementing API version 1.21.10-R0.1-SNAPSHOT)
You are running the latest version
Previous version: 1.21.10-2535-0a2dc04 (MC: 1.21.10)

### Other

_No response_

[Pen92he]

[Pen92he]

After conducting self testing over the past few days, we have come to the conclusion that:

1. I read the Basic troubleshooting in the paper and tried the first step - disable all of plugins. I found that the problem still exists, and chunk data is still damaged, specifically manifested as the disappearance or incompleteness of existing buildings and terrain in the server
2. Next, proceed to the second step - attempt to force the server to downgrade to 1.20.4- use flag DPaper. ignoreWorldDataVersion=true,
   well, A miracle has occurred, the problem has been solved, and there will be no more bad blocks or stack traces. The buildings in the game will not be damaged or disappear,
   So I think this belongs to some bugs in the paper. If you need me to provide anything, I am happy to help

[Pen92he]

Just like this, on 1.21.10, the player's house is only half left (which is quite unfortunate)

[Malfrador]

Ignoring heightmap data for chunk [-5, 419], size does not match; expected: 37, got: 43

This usually indicates that you changed your world height using a datapack or plugin, and now removed this datapack/plugin or it failed to load properly.
This will result in everything outside the vanilla world height being deleted.

Best advice would be to restore from a backup, and to ensure your height changing datapack correctly works on 1.21.10.
This is very unlikely to be an issue with Paper.

[Pen92he]

Ignoring heightmap data for chunk [-5, 419], size does not match; expected: 37, got: 43

This usually indicates that you changed your world height using a datapack or plugin, and now removed this datapack/plugin or it failed to load properly. This will result in everything outside the vanilla world height being deleted.

Best advice would be to restore from a backup, and to ensure your height changing datapack correctly works on 1.21.10. This is very unlikely to be an issue with Paper.

Yes, in fact, I used the Iris plugin on version 1.20.4, which changed the height of the server and caused the console to appear Ignoring heightmap data for chunk [-5, 419], size does not match; Expected: 37, got: 43 reminder, but no chunk data loss occurred. Upgrading to 1.21.10 may cause this issue. Is this related to changing the chunk loading mechanism?

[Pen92he]

The problem has been resolved, it is an issue with the Iris plugin. I have used it VolmitSoftware/Iris#1163 The problem was solved using the same method. Thank you for your patient answer. Please close this