---- Minecraft Crash Report ----
// Shall we play a game?

Time: 2025-11-22 21:22:53
Description: Updated chunk

java.util.ConcurrentModificationException
	at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1229)
	at net.minecraft.world.level.levelgen.structure.LegacyStructureDataHandler.lambda$populateCaches$6(LegacyStructureDataHandler.java:259)
	at java.base/java.util.Optional.ifPresent(Optional.java:178)
	at net.minecraft.world.level.levelgen.structure.LegacyStructureDataHandler.lambda$populateCaches$7(LegacyStructureDataHandler.java:258)
	at java.base/java.util.HashMap.forEach(HashMap.java:1429)
	at net.minecraft.nbt.CompoundTag.forEach(CompoundTag.java:228)
	at net.minecraft.world.level.levelgen.structure.LegacyStructureDataHandler.populateCaches(LegacyStructureDataHandler.java:245)
	at net.minecraft.world.level.levelgen.structure.LegacyStructureDataHandler.applyFix(LegacyStructureDataHandler.java:119)
	at net.minecraft.world.level.chunk.storage.SimpleRegionStorage.upgradeChunkTag(SimpleRegionStorage.java:65)
	at net.minecraft.server.level.ChunkMap.upgradeChunkTag(ChunkMap.java:974)
	at java.base/java.util.Optional.map(Optional.java:260)
	at net.minecraft.server.level.ChunkMap.lambda$readChunk$35(ChunkMap.java:970)
	at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:646)
	at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:483)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Thread: Server thread
Stacktrace:
	at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1229)
	at net.minecraft.world.level.levelgen.structure.LegacyStructureDataHandler.lambda$populateCaches$6(LegacyStructureDataHandler.java:259)
	at java.base/java.util.Optional.ifPresent(Optional.java:178)
	at net.minecraft.world.level.levelgen.structure.LegacyStructureDataHandler.lambda$populateCaches$7(LegacyStructureDataHandler.java:258)
	at java.base/java.util.HashMap.forEach(HashMap.java:1429)
	at net.minecraft.nbt.CompoundTag.forEach(CompoundTag.java:228)
	at net.minecraft.world.level.levelgen.structure.LegacyStructureDataHandler.populateCaches(LegacyStructureDataHandler.java:245)
	at net.minecraft.world.level.levelgen.structure.LegacyStructureDataHandler.applyFix(LegacyStructureDataHandler.java:119)

-- Updated chunk details --
Details:
	Data version: 4663
Stacktrace:
	at net.minecraft.world.level.chunk.storage.SimpleRegionStorage.upgradeChunkTag(SimpleRegionStorage.java:65)
	at net.minecraft.server.level.ChunkMap.upgradeChunkTag(ChunkMap.java:974)
	at java.base/java.util.Optional.map(Optional.java:260)
	at net.minecraft.server.level.ChunkMap.lambda$readChunk$35(ChunkMap.java:970)
	at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:646)
	at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:483)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)

-- Chunk being loaded --
Details:
	pos: [-12, 14]
Stacktrace:
	at net.minecraft.server.level.ChunkMap.handleChunkLoadFailure(ChunkMap.java:626)
	at net.minecraft.server.level.ChunkMap.lambda$scheduleChunkLoad$18(ChunkMap.java:615)
	at java.base/java.util.concurrent.CompletableFuture.uniExceptionally(CompletableFuture.java:990)
	at java.base/java.util.concurrent.CompletableFuture$UniExceptionally.tryFire(CompletableFuture.java:974)
	at java.base/java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:482)
	at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:169)
	at net.minecraft.server.level.ServerChunkCache$MainThreadExecutor.doRunTask(ServerChunkCache.java:625)
	at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:143)
	at net.minecraft.server.level.ServerChunkCache$MainThreadExecutor.pollTask(ServerChunkCache.java:634)
	at net.minecraft.server.level.ServerChunkCache.pollTask(ServerChunkCache.java:272)
	at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:935)
	at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:923)
	at net.minecraft.util.thread.BlockableEventLoop.managedBlock(BlockableEventLoop.java:152)
	at net.minecraft.server.MinecraftServer.managedBlock(MinecraftServer.java:883)
	at net.minecraft.server.MinecraftServer.waitUntilNextTick(MinecraftServer.java:894)
	at net.minecraft.server.MinecraftServer.prepareLevels(MinecraftServer.java:596)
	at net.minecraft.server.MinecraftServer.loadLevel(MinecraftServer.java:392)
	at net.minecraft.client.server.IntegratedServer.initServer(IntegratedServer.java:83)
	at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:738)
	at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:300)
	at java.base/java.lang.Thread.run(Thread.java:1583)

-- System Details --
Details:
	Minecraft Version: 1.21.11 Pre-Release 2 Unobfuscated
	Minecraft Version ID: 1.21.11-pre2_unobfuscated
	Operating System: Windows 11 (amd64) version 10.0
	Java Version: 21.0.8, Microsoft
	Java VM Version: OpenJDK 64-Bit Server VM (mixed mode, sharing), Microsoft
	Memory: 194066912 bytes (185 MiB) / 520093696 bytes (496 MiB) up to 2361393152 bytes (2252 MiB)
	CPUs: 16
	Processor Vendor: GenuineIntel
	Processor Name: 13th Gen Intel(R) Core(TM) i5-13500H
	Identifier: Intel64 Family 6 Model 186 Stepping 2
	Microarchitecture: Raptor Lake
	Frequency (GHz): 3.19
	Number of physical packages: 1
	Number of physical CPUs: 12
	Number of logical CPUs: 16
	Graphics card #0 name: Intel(R) Iris(R) Xe Graphics
	Graphics card #0 vendor: Intel Corporation
	Graphics card #0 VRAM (MiB): 2048.00
	Graphics card #0 deviceId: VideoController1
	Graphics card #0 versionInfo: 32.0.101.6647
	Memory slot #0 capacity (MiB): 2048.00
	Memory slot #0 clockSpeed (GHz): 6.40
	Memory slot #0 type: LPDDR5
	Memory slot #1 capacity (MiB): 2048.00
	Memory slot #1 clockSpeed (GHz): 6.40
	Memory slot #1 type: LPDDR5
	Memory slot #2 capacity (MiB): 2048.00
	Memory slot #2 clockSpeed (GHz): 6.40
	Memory slot #2 type: LPDDR5
	Memory slot #3 capacity (MiB): 2048.00
	Memory slot #3 clockSpeed (GHz): 6.40
	Memory slot #3 type: LPDDR5
	Memory slot #4 capacity (MiB): 2048.00
	Memory slot #4 clockSpeed (GHz): 6.40
	Memory slot #4 type: LPDDR5
	Memory slot #5 capacity (MiB): 2048.00
	Memory slot #5 clockSpeed (GHz): 6.40
	Memory slot #5 type: LPDDR5
	Memory slot #6 capacity (MiB): 2048.00
	Memory slot #6 clockSpeed (GHz): 6.40
	Memory slot #6 type: LPDDR5
	Memory slot #7 capacity (MiB): 2048.00
	Memory slot #7 clockSpeed (GHz): 6.40
	Memory slot #7 type: LPDDR5
	Virtual memory max (MiB): 35345.34
	Virtual memory used (MiB): 23244.81
	Swap memory total (MiB): 19236.47
	Swap memory used (MiB): 7632.25
	Space in storage for jna.tmpdir (MiB): available: 30210.94, total: 235915.00
	Space in storage for org.lwjgl.system.SharedLibraryExtractPath (MiB): available: 30210.94, total: 235915.00
	Space in storage for io.netty.native.workdir (MiB): available: 30210.94, total: 235915.00
	Space in storage for java.io.tmpdir (MiB): available: 30210.94, total: 235915.00
	Space in storage for workdir (MiB): available: 30210.94, total: 235915.00
	JVM Flags: 6 total; -XX:+UseG1GC -XX:-UseAdaptiveSizePolicy -XX:-OmitStackTraceInFastThrow -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmn450m -Xmx2252m
	Debug Flags: 0 total; 
	Server Running: true
	Player Count: 0 / 8; []
	Active Data Packs: vanilla
	Available Data Packs: minecart_improvements, redstone_experiments, trade_rebalance, vanilla
	Enabled Feature Flags: minecraft:vanilla
	World Generation: Stable
	World Seed: 4256825463603229770
	Suppressed Exceptions: ~~NONE~~
	Type: Integrated Server
	Is Modded: Probably not. Client jar signature and brand is untouched; Server jar signature and brand is untouched
	Launched Version: 1_21_11-pre2_unobfuscated