Crash Report

---- Minecraft Crash Report ----
// Who set us up the TNT?

Time: 7/9/14 5:30 PM
Description: Exception ticking world

java.lang.IllegalArgumentException: Cannot set property bck{name=facing, clazz=class ei, values=[down, up, north, south, west, east]} to null on block minecraft:piston_extension, it is not an allowed value
	at bbw.a(SourceFile:103)
	at bbn.b(SourceFile:208)
	at bbi.a(SourceFile:365)
	at bbi.a(SourceFile:152)
	at qg.a(SourceFile:853)
	at qg.aj(SourceFile:842)
	at qg.c(SourceFile:214)
	at net.minecraft.server.MinecraftServer.x(SourceFile:578)
	at net.minecraft.server.MinecraftServer.w(SourceFile:510)
	at cwg.w(SourceFile:132)
	at net.minecraft.server.MinecraftServer.run(SourceFile:426)
	at java.lang.Thread.run(Thread.java:744)


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

-- Head --
Stacktrace:
	at bbw.a(SourceFile:103)
	at bbn.b(SourceFile:208)
	at bbi.a(SourceFile:365)
	at bbi.a(SourceFile:152)
	at qg.a(SourceFile:853)
	at qg.aj(SourceFile:842)
	at qg.c(SourceFile:214)

-- Affected level --
Details:
	Level name: The Adventure
	All players: 1 total; [qj['wwatso1'/2, l='The Adventure', x=51.85, y=69.00, z=628.47]]
	Chunk stats: ServerChunkCache: 746 Drop: 0
	Level seed: 2083196593536395200
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 3;minecraft:bedrock,3*minecraft:stone,52*minecraft:dirt,minecraft:grass;2;
	Level spawn location: 82.00,4.00,617.00 - World: (82,4,617), Chunk: (at 2,0,9 in 5,38; contains blocks 80,0,608 to 95,255,623), Region: (0,1; contains chunks 0,32 to 31,63, blocks 0,0,512 to 511,255,1023)
	Level time: 102499 game time, 1176 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 74760 (now: false), thunder time: 128814 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.x(SourceFile:578)
	at net.minecraft.server.MinecraftServer.w(SourceFile:510)
	at cwg.w(SourceFile:132)
	at net.minecraft.server.MinecraftServer.run(SourceFile:426)
	at java.lang.Thread.run(Thread.java:744)

-- System Details --
Details:
	Minecraft Version: 14w28a
	Operating System: Linux (amd64) version 3.11.0-12-generic
	Java Version: 1.7.0_51, Oracle Corporation
	Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 120164096 bytes (114 MB) / 438304768 bytes (418 MB) up to 954728448 bytes (910 MB)
	JVM Flags: 1 total; -Xmx1G
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [qj['wwatso1'/2, l='The Adventure', x=51.85, y=69.00, z=628.47]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.