---- Minecraft Crash Report ----
// Everything's going to plan. No, really, that was supposed to happen.

Time: 13.04.19 15:53
Description: Exception while updating neighbours

java.lang.IllegalStateException: POI data mismatch: already registered at ev{x=3687, y=64, z=-5331}
	at aqc.a(SourceFile:81)
	at aqc.a(SourceFile:65)
	at aqa.a(SourceFile:43)
	at vf.b(SourceFile:1287)
	at vf$$Lambda$3074/1564236335.run(Unknown Source)
	at agf.execute(SourceFile:90)
	at vf.a(SourceFile:1286)
	at vf$$Lambda$3073/1093859386.accept(Unknown Source)
	at java.util.Optional.ifPresent(Optional.java:159)
	at vf.a(SourceFile:1286)
	at bha.a(SourceFile:252)
	at cjb.a(SourceFile:219)
	at cjb.b(SourceFile:178)
	at cjb.a(SourceFile:174)
	at buf.c(SourceFile:430)
	at brt.a(SourceFile:101)
	at brt.a(SourceFile:89)
	at bvc.a(SourceFile:242)
	at bha.a(SourceFile:354)
	at bpv.a(SourceFile:71)
	at bpv.b(SourceFile:49)
	at bvc.a(SourceFile:262)
	at vf.b(SourceFile:563)
	at vf$$Lambda$2552/995360757.accept(Unknown Source)
	at bhn.a(SourceFile:76)
	at vf.a(SourceFile:315)
	at net.minecraft.server.MinecraftServer.b(SourceFile:827)
	at net.minecraft.server.MinecraftServer.a(SourceFile:764)
	at dxa.a(SourceFile:128)
	at net.minecraft.server.MinecraftServer.run(SourceFile:632)
	at java.lang.Thread.run(Thread.java:745)


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

-- Head --
Thread: Server thread
Stacktrace:
	at aqc.a(SourceFile:81)
	at aqc.a(SourceFile:65)
	at aqa.a(SourceFile:43)
	at vf.b(SourceFile:1287)
	at vf$$Lambda$3074/1564236335.run(Unknown Source)
	at agf.execute(SourceFile:90)
	at vf.a(SourceFile:1286)
	at vf$$Lambda$3073/1093859386.accept(Unknown Source)
	at java.util.Optional.ifPresent(Optional.java:159)
	at vf.a(SourceFile:1286)
	at bha.a(SourceFile:252)
	at cjb.a(SourceFile:219)
	at cjb.b(SourceFile:178)
	at cjb.a(SourceFile:174)
	at buf.c(SourceFile:430)
	at brt.a(SourceFile:101)
	at brt.a(SourceFile:89)
	at bvc.a(SourceFile:242)

-- Block being updated --
Details:
	Source block type: ID #minecraft:observer (block.minecraft.observer // bpv)
	Block: Block{minecraft:structure_block}[mode=load]
	Block location: World: (3680,69,-5358), Chunk: (at 0,4,2 in 230,-335; contains blocks 3680,0,-5360 to 3695,255,-5345), Region: (7,-11; contains chunks 224,-352 to 255,-321, blocks 3584,0,-5632 to 4095,255,-5121)
Stacktrace:
	at bha.a(SourceFile:354)
	at bpv.a(SourceFile:71)
	at bpv.b(SourceFile:49)
	at bvc.a(SourceFile:262)
	at vf.b(SourceFile:563)
	at vf$$Lambda$2552/995360757.accept(Unknown Source)

-- Block being ticked --
Details:
	Block location: World: (3681,69,-5358), Chunk: (at 1,4,2 in 230,-335; contains blocks 3680,0,-5360 to 3695,255,-5345), Region: (7,-11; contains chunks 224,-352 to 255,-321, blocks 3584,0,-5632 to 4095,255,-5121)
Stacktrace:
	at bhn.a(SourceFile:76)
	at vf.a(SourceFile:315)

-- Affected level --
Details:
	Level name: Igloo Test
	All players: 1 total; [vg['Maxel_123'/17081, l='Igloo Test', x=3483.17, y=79.47, z=-5442.97]]
	Chunk stats: ServerChunkCache: 4781
	Level seed: -3107103250153560940
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: {}
	Level spawn location: World: (96,68,241), Chunk: (at 0,4,1 in 6,15; contains blocks 96,0,240 to 111,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 944429 game time, 6000 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.b(SourceFile:827)
	at net.minecraft.server.MinecraftServer.a(SourceFile:764)
	at dxa.a(SourceFile:128)
	at net.minecraft.server.MinecraftServer.run(SourceFile:632)
	at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
	Minecraft Version: 1.14 Pre-Release 2
	Operating System: Windows 8.1 (amd64) version 6.3
	Java Version: 1.8.0_51, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 1046096200 bytes (997 MB) / 2013265920 bytes (1920 MB) up to 2147483648 bytes (2048 MB)
	JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
	Player Count: 1 / 8; [vg['Maxel_123'/17081, l='Igloo Test', x=3483.17, y=79.47, z=-5442.97]]
	Data Packs: vanilla, file/Illager Fortress v1 [1.14] (incompatible)
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.