ensureTickThread exception on shutdown

Stack trace

[22:34:24] [ServerMain/INFO]: [bootstrap] Running Java 21 (OpenJDK 64-Bit Server VM 21.0.6+7; Arch Linux null) on Linux 6.12.16-1-lts (amd64)
[22:34:24] [ServerMain/INFO]: [bootstrap] Loading Paper 1.21.4-207-main@1a7288a (2025-03-09T18:15:59Z) for Minecraft 1.21.4
[22:34:25] [ServerMain/INFO]: [PluginInitializerManager] Initializing plugins...
[22:34:25] [ServerMain/INFO]: [PluginInitializerManager] Initialized 0 plugins
[22:34:27] [ServerMain/INFO]: Environment: Environment[sessionHost=https://sessionserver.mojang.com, servicesHost=https://api.minecraftservices.com, name=PROD]
[22:34:28] [ServerMain/INFO]: Loaded 1370 recipes
[22:34:28] [ServerMain/INFO]: Loaded 1481 advancements
[22:34:28] [ServerMain/INFO]: [MCTypeRegistry] Initialising converters for DataConverter...
[22:34:28] [ServerMain/INFO]: [MCTypeRegistry] Finished initialising converters for DataConverter in 122.7ms
[22:34:28] [Server thread/INFO]: Starting minecraft server version 1.21.4
[22:34:28] [Server thread/INFO]: Loading properties
[22:34:28] [Server thread/INFO]: This server is running Paper version 1.21.4-207-main@1a7288a (2025-03-09T18:15:59Z) (Implementing API version 1.21.4-R0.1-SNAPSHOT)
[22:34:28] [Server thread/INFO]: [spark] This server bundles the spark profiler. For more information please visit https://docs.papermc.io/paper/profiling
[22:34:28] [Server thread/INFO]: Server Ping Player Sample Count: 12
[22:34:28] [Server thread/INFO]: Using 4 threads for Netty based IO
[22:34:29] [Server thread/INFO]: [MoonriseCommon] Paper is using 4 worker threads, 1 I/O threads
[22:34:29] [Server thread/INFO]: [ChunkTaskScheduler] Chunk system is using population gen parallelism: true
[22:34:29] [Server thread/INFO]: Default game type: SURVIVAL
[22:34:29] [Server thread/INFO]: Generating keypair
[22:34:29] [Server thread/INFO]: Starting Minecraft server on *:25565
[22:34:29] [Server thread/INFO]: Using epoll channel type
[22:34:29] [Server thread/INFO]: Paper: Using libdeflate (Linux x86_64) compression from Velocity.
[22:34:29] [Server thread/INFO]: Paper: Using OpenSSL 3.x.x (Linux x86_64) cipher from Velocity.
[22:34:29] [Server thread/INFO]: Server permissions file permissions.yml is empty, ignoring it
[22:34:29] [Server thread/INFO]: Preparing level "world"
[22:34:29] [Server thread/INFO]: Preparing start region for dimension minecraft:overworld
[22:34:29] [Server thread/INFO]: Preparing spawn area: 0%
[22:34:29] [Server thread/INFO]: Time elapsed: 225 ms
[22:34:29] [Server thread/INFO]: Preparing start region for dimension minecraft:the_nether
[22:34:29] [Server thread/INFO]: Preparing spawn area: 0%
[22:34:29] [Server thread/INFO]: Time elapsed: 75 ms
[22:34:29] [Server thread/INFO]: Preparing start region for dimension minecraft:the_end
[22:34:29] [Server thread/INFO]: Preparing spawn area: 0%
[22:34:30] [Server thread/INFO]: Time elapsed: 218 ms
[22:34:30] [Server thread/INFO]: [spark] Starting background profiler...
[22:34:30] [Server thread/INFO]: Done preparing level "world" (0.876s)
[22:34:30] [Server thread/INFO]: Running delayed init tasks
[22:34:30] [Server thread/INFO]: Done (5.690s)! For help, type "help"
[22:34:35] [User Authenticator #0/INFO]: UUID of player ...
[22:34:35] [Server thread/INFO]: ... joined the game
[22:34:35] [Server thread/INFO]: ... logged in with entity id 11 at ([world]2.5, 72.0, 1.5)
<Ctrl+C>
[22:34:40] [Server thread/INFO]: Stopping server
[22:34:40] [Server thread/INFO]: Saving players
[22:34:40] [Paper Common Worker #0/ERROR]: [ca.spottedleaf.moonrise.common.util.TickThread] Thread failed main thread check: Accessing poi chunk off-main, context=thread=Paper Common Worker #0, world=world, chunk_pos=[5, 13]
java.lang.Throwable: null
	at ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread(TickThread.java:64) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.entity.ai.village.poi.PoiManager.getOrLoad(PoiManager.java:87) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.entity.ai.village.poi.PoiManager.exists(PoiManager.java:336) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.server.level.ServerLevel.lambda$onBlockStateChange$17(ServerLevel.java:2221) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.util.thread.BlockableEventLoop.execute(BlockableEventLoop.java:105) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.server.level.ServerLevel.lambda$onBlockStateChange$18(ServerLevel.java:2219) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at java.base/java.util.Optional.ifPresent(Optional.java:178) ~[?:?]
	at net.minecraft.server.level.ServerLevel.onBlockStateChange(ServerLevel.java:2219) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.server.level.WorldGenRegion.setBlock(WorldGenRegion.java:345) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.LevelWriter.setBlock(LevelWriter.java:12) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplate.placeInWorld(StructureTemplate.java:315) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.pools.SinglePoolElement.place(SinglePoolElement.java:154) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.PoolElementStructurePiece.place(PoolElementStructurePiece.java:115) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.PoolElementStructurePiece.postProcess(PoolElementStructurePiece.java:102) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.StructureStart.placeInChunk(StructureStart.java:108) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.ChunkGenerator.lambda$addVanillaDecorations$10(ChunkGenerator.java:374) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at com.google.common.collect.ImmutableList.forEach(ImmutableList.java:423) ~[guava-33.3.1-jre.jar:?]
	at net.minecraft.world.level.chunk.ChunkGenerator.addVanillaDecorations(ChunkGenerator.java:373) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.ChunkGenerator.applyBiomeDecoration(ChunkGenerator.java:447) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.ChunkGenerator.applyBiomeDecoration(ChunkGenerator.java:442) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.status.ChunkStatusTasks.generateFeatures(ChunkStatusTasks.java:145) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.status.ChunkStep.apply(ChunkStep.java:66) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkUpgradeGenericStatusTask.run(ChunkUpgradeGenericStatusTask.java:99) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.executor.RadiusAwarePrioritisedExecutor$Task.run(RadiusAwarePrioritisedExecutor.java:492) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.concurrentutil.executor.queue.PrioritisedTaskQueue$PrioritisedQueuedTask.execute(PrioritisedTaskQueue.java:281) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.queue.PrioritisedTaskQueue.executeTask(PrioritisedTaskQueue.java:101) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedThreadPool$ExecutorGroup$ThreadPoolExecutor.executeTask(PrioritisedThreadPool.java:533) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedThreadPool$PrioritisedThread.pollTasks(PrioritisedThreadPool.java:354) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.doRun(PrioritisedQueueExecutorThread.java:60) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.run(PrioritisedQueueExecutorThread.java:49) ~[concurrentutil-0.0.3.jar:?]
[22:34:40] [Server thread/INFO]: ... lost connection: Server closed
[22:34:40] [Server thread/INFO]: ... left the game
[22:34:40] [Server thread/INFO]: Saving worlds
[22:34:40] [Server thread/INFO]: Saving chunks for level 'ServerLevel[world]'/minecraft:overworld
[22:34:40] [Server thread/INFO]: [ChunkHolderManager] Waiting 60s for chunk system to halt for world 'world'
[22:34:40] [Paper Common Worker #0/ERROR]: [ChunkTaskScheduler] Chunk system error at chunk (5,13), holder: NewChunkHolder{world=world, chunkX=5, chunkZ=13, entityChunkFromDisk=false, lastChunkCompletion={chunk_class=net.minecraft.world.level.chunk.ProtoChunk,status=minecraft:carvers}, currentGenStatus=minecraft:carvers, requestedGenStatus=minecraft:initialize_light, generationTask=ChunkProgressionTask{class: ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkUpgradeGenericStatusTask, for world: world, chunk: (5,13), hashcode: 1484384579, priority: COMPLETING, status: minecraft:features, scheduled: true}, generationTaskStatus=minecraft:features, priority=null, priorityLocked=false, neighbourRequestedPriority=null, effective_priority=null, oldTicketLevel=34, currentTicketLevel=34, totalNeighboursUsingThisChunk=1, fullNeighbourChunksLoadedBitset=39, currentChunkStatus=INACCESSIBLE, pendingChunkStatus=INACCESSIBLE, is_unload_safe=ticket_level, killed=false}, exception:
java.lang.Throwable: net.minecraft.ReportedException: Feature placement
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.unrecoverableChunkSystemFailure(ChunkTaskScheduler.java:313) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder.lambda$setGenerationTask$5(NewChunkHolder.java:1627) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkProgressionTask.complete0(ChunkProgressionTask.java:91) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkProgressionTask.complete(ChunkProgressionTask.java:74) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkUpgradeGenericStatusTask.run(ChunkUpgradeGenericStatusTask.java:116) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.executor.RadiusAwarePrioritisedExecutor$Task.run(RadiusAwarePrioritisedExecutor.java:492) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.concurrentutil.executor.queue.PrioritisedTaskQueue$PrioritisedQueuedTask.execute(PrioritisedTaskQueue.java:281) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.queue.PrioritisedTaskQueue.executeTask(PrioritisedTaskQueue.java:101) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedThreadPool$ExecutorGroup$ThreadPoolExecutor.executeTask(PrioritisedThreadPool.java:533) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedThreadPool$PrioritisedThread.pollTasks(PrioritisedThreadPool.java:354) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.doRun(PrioritisedQueueExecutorThread.java:60) ~[concurrentutil-0.0.3.jar:?]
	at ca.spottedleaf.concurrentutil.executor.thread.PrioritisedQueueExecutorThread.run(PrioritisedQueueExecutorThread.java:49) ~[concurrentutil-0.0.3.jar:?]
Caused by: net.minecraft.ReportedException: Feature placement
	at net.minecraft.world.level.chunk.ChunkGenerator.addVanillaDecorations(ChunkGenerator.java:436) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.ChunkGenerator.applyBiomeDecoration(ChunkGenerator.java:447) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.ChunkGenerator.applyBiomeDecoration(ChunkGenerator.java:442) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.status.ChunkStatusTasks.generateFeatures(ChunkStatusTasks.java:145) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.status.ChunkStep.apply(ChunkStep.java:66) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkUpgradeGenericStatusTask.run(ChunkUpgradeGenericStatusTask.java:99) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	... 7 more
Caused by: java.lang.IllegalStateException: Thread failed main thread check: Accessing poi chunk off-main, context=thread=Paper Common Worker #0, world=world, chunk_pos=[5, 13]
	at ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread(TickThread.java:65) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.entity.ai.village.poi.PoiManager.getOrLoad(PoiManager.java:87) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.entity.ai.village.poi.PoiManager.exists(PoiManager.java:336) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.server.level.ServerLevel.lambda$onBlockStateChange$17(ServerLevel.java:2221) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.util.thread.BlockableEventLoop.execute(BlockableEventLoop.java:105) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.server.level.ServerLevel.lambda$onBlockStateChange$18(ServerLevel.java:2219) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at java.base/java.util.Optional.ifPresent(Optional.java:178) ~[?:?]
	at net.minecraft.server.level.ServerLevel.onBlockStateChange(ServerLevel.java:2219) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.server.level.WorldGenRegion.setBlock(WorldGenRegion.java:345) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.LevelWriter.setBlock(LevelWriter.java:12) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplate.placeInWorld(StructureTemplate.java:315) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.pools.SinglePoolElement.place(SinglePoolElement.java:154) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.PoolElementStructurePiece.place(PoolElementStructurePiece.java:115) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.PoolElementStructurePiece.postProcess(PoolElementStructurePiece.java:102) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.levelgen.structure.StructureStart.placeInChunk(StructureStart.java:108) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.ChunkGenerator.lambda$addVanillaDecorations$10(ChunkGenerator.java:374) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at com.google.common.collect.ImmutableList.forEach(ImmutableList.java:423) ~[guava-33.3.1-jre.jar:?]
	at net.minecraft.world.level.chunk.ChunkGenerator.addVanillaDecorations(ChunkGenerator.java:373) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.ChunkGenerator.applyBiomeDecoration(ChunkGenerator.java:447) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.ChunkGenerator.applyBiomeDecoration(ChunkGenerator.java:442) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.status.ChunkStatusTasks.generateFeatures(ChunkStatusTasks.java:145) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at net.minecraft.world.level.chunk.status.ChunkStep.apply(ChunkStep.java:66) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	at ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkUpgradeGenericStatusTask.run(ChunkUpgradeGenericStatusTask.java:99) ~[paper-1.21.4.jar:1.21.4-207-1a7288a]
	... 7 more
[22:34:40] [Server thread/INFO]: [ChunkHolderManager] Halted chunk system for world 'world'
[22:34:40] [Server thread/INFO]: [ChunkHolderManager] Saving all chunkholders for world 'world'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Saved 913 block chunks, 483 entity chunks, 2 poi chunks in world 'world' in 0.36s
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Waiting 60s for chunk I/O to halt for world 'world'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Halted I/O scheduler for world 'world'
[22:34:41] [Server thread/INFO]: Saving chunks for level 'ServerLevel[world_nether]'/minecraft:the_nether
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Waiting 60s for chunk system to halt for world 'world_nether'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Halted chunk system for world 'world_nether'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Saving all chunkholders for world 'world_nether'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Saved 49 block chunks, 49 entity chunks, 0 poi chunks in world 'world_nether' in 0.02s
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Waiting 60s for chunk I/O to halt for world 'world_nether'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Halted I/O scheduler for world 'world_nether'
[22:34:41] [Server thread/INFO]: Saving chunks for level 'ServerLevel[world_the_end]'/minecraft:the_end
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Waiting 60s for chunk system to halt for world 'world_the_end'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Halted chunk system for world 'world_the_end'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Saving all chunkholders for world 'world_the_end'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Saved 49 block chunks, 49 entity chunks, 0 poi chunks in world 'world_the_end' in 0.01s
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Waiting 60s for chunk I/O to halt for world 'world_the_end'
[22:34:41] [Server thread/INFO]: [ChunkHolderManager] Halted I/O scheduler for world 'world_the_end'
[22:34:41] [Server thread/INFO]: ThreadedAnvilChunkStorage (world): All chunks are saved
[22:34:41] [Server thread/INFO]: ThreadedAnvilChunkStorage (DIM-1): All chunks are saved
[22:34:41] [Server thread/INFO]: ThreadedAnvilChunkStorage (DIM1): All chunks are saved
[22:34:41] [Server thread/INFO]: ThreadedAnvilChunkStorage: All dimensions are saved
[22:34:41] [Server thread/INFO]: Waiting for I/O tasks to complete...
[22:34:41] [Server thread/INFO]: All I/O tasks to complete
[22:34:41] [Server thread/INFO]: [MoonriseCommon] Awaiting termination of worker pool for up to 60s...
[22:34:41] [Server thread/INFO]: [MoonriseCommon] Awaiting termination of I/O pool for up to 60s...

Plugin and Datapack List

None

Actions to reproduce (if known)

Could not reproduce on subsequent runs, probably because the chunks are generate.

Paper version

This server is running Paper version 1.21.4-207-main@1a7288a (2025-03-09T18:15:59Z) (Implementing API version 1.21.4-R0.1-SNAPSHOT)

Other

No plugins.
Server was stopped with Ctrl+C.
One player in spawn chunks, some chunks already generated.
Default configs.

Start with ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread and follow the reported calls through PoiManager, ServerLevel, ChunkGenerator, and the chunk scheduler. Reproduce the shutdown sequence shown in the log and determine why feature placement continues during shutdown; done means the shutdown no longer produces this thread-check or chunk-system error.