---- Minecraft Crash Report ----
// Why is it breaking :(

Time: 22-4-16 2:37
Description: Exception ticking world

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.remove(Unknown Source)
	at lp.d(SourceFile:198)
	at lq.d(SourceFile:201)
	at net.minecraft.server.MinecraftServer.D(SourceFile:618)
	at net.minecraft.server.MinecraftServer.C(SourceFile:554)
	at byk.C(SourceFile:155)
	at net.minecraft.server.MinecraftServer.run(SourceFile:458)
	at java.lang.Thread.run(Unknown Source)


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

-- Head --
Stacktrace:
	at java.util.HashMap$HashIterator.remove(Unknown Source)
	at lp.d(SourceFile:198)
	at lq.d(SourceFile:201)

-- Affected level --
Details:
	Level name: Item Storage
	All players: 0 total; []
	Chunk stats: ServerChunkCache: 443 Drop: 188
	Level seed: 6436031529423484831
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 3;minecraft:bedrock,3*minecraft:stone,52*minecraft:sandstone;2;
	Level spawn location: World: (0,56,0), Chunk: (at 0,3,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 3699833 game time, 1000 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 37268 (now: false), thunder time: 99388 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.D(SourceFile:618)
	at net.minecraft.server.MinecraftServer.C(SourceFile:554)
	at byk.C(SourceFile:155)
	at net.minecraft.server.MinecraftServer.run(SourceFile:458)
	at java.lang.Thread.run(Unknown Source)

-- System Details --
Details:
	Minecraft Version: 1.9.3-pre1
	Operating System: Windows 10 (x86) version 10.0
	Java Version: 1.8.0_73, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 241018416 bytes (229 MB) / 397164544 bytes (378 MB) up to 523501568 bytes (499 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Player Count: 0 / 8; []
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.