crash with f3 on tripwire

---- Minecraft Crash Report ----
// Hey, that tickles! Hehehe!

Time: 9-7-14 19:35
Description: Unexpected error

java.lang.IllegalArgumentException: Cannot get property bci{name=north, clazz=class java.lang.Boolean, values=[true, false]} as it does not exist!
	at bbw.b(SourceFile:91)
	at azn.c(SourceFile:221)
	at azn.a(SourceFile:51)
	at brw.c(SourceFile:152)
	at brw.b(SourceFile:69)
	at brw.a(SourceFile:46)
	at brm.a(SourceFile:205)
	at cir.b(SourceFile:994)
	at bqi.ap(SourceFile:888)
	at bqi.a(SourceFile:303)
	at net.minecraft.client.main.Main.main(SourceFile:120)


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

-- Head --
Stacktrace:
	at bbw.b(SourceFile:91)
	at azn.c(SourceFile:221)
	at azn.a(SourceFile:51)
	at brw.c(SourceFile:152)
	at brw.b(SourceFile:69)
	at brw.a(SourceFile:46)
	at brm.a(SourceFile:205)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [chv['FVbico'/0, l='MpServer', x=240,33, y=60,05, z=799,04]]
	Chunk stats: MultiplayerChunkCache: 439, 439
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: 240,00,60,00,816,00 - World: (240,60,816), Chunk: (at 0,3,0 in 15,51; contains blocks 240,0,816 to 255,255,831), Region: (0,1; contains chunks 0,32 to 31,63, blocks 0,0,512 to 511,255,1023)
	Level time: 33699577 game time, 22000 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: adventure (ID 2). Hardcore: false. Cheats: false
	Forced entities: 1 total; [chv['FVbico'/0, l='MpServer', x=240,33, y=60,05, z=799,04]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Non-integrated multiplayer server
Stacktrace:
	at cdu.a(SourceFile:308)
	at bqi.b(SourceFile:2139)
	at bqi.a(SourceFile:317)
	at net.minecraft.client.main.Main.main(SourceFile:120)

-- System Details --
Details:
	Minecraft Version: 14w28a
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_55, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 185101248 bytes (176 MB) / 372035584 bytes (354 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 14w28a
	LWJGL: 2.9.1
	OpenGL: AMD Radeon HD 6800 Series GL version 4.3.12618 Compatibility Profile Context 13.251.0.0, ATI Technologies Inc.
	GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.

	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: []
	Current Language: English (US)
	Profiler Position: N/A (disabled)