Hopper: java.lang.NullPointerException: Can't place skulls in multiplayer

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-1464769/

Crash:

java.lang.NullPointerException: Unexpected error
	at att.d(SourceFile:88)
	at att.a(SourceFile:77)
	at ahf.a(SourceFile:79)
	at agh.a(SourceFile:122)
	at bqq.a(SourceFile:304)
	at bfr.ak(SourceFile:1256)

The following is the first clean report made public about this crash:

---- Minecraft Crash Report ----
// My bad.

Time: 13.03.14 18:51
Description: Unexpected error

java.lang.NullPointerException: Unexpected error
	at att.d(SourceFile:88)
	at att.a(SourceFile:77)
	at ahf.a(SourceFile:79)
	at agh.a(SourceFile:122)
	at bqq.a(SourceFile:304)
	at bfr.ak(SourceFile:1256)
	at bfr.p(SourceFile:1602)
	at bfr.ai(SourceFile:801)
	at bfr.f(SourceFile:755)
	at net.minecraft.client.main.Main.main(SourceFile:121)


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

-- Head --
Stacktrace:
	at att.d(SourceFile:88)
	at att.a(SourceFile:77)
	at ahf.a(SourceFile:79)
	at agh.a(SourceFile:122)
	at bqq.a(SourceFile:304)
	at bfr.ak(SourceFile:1256)

-- Affected level --
Details:
	Level name: MpServer
	All players: 3 total; [bsv['Zombiefighter331'/2299, l='MpServer', x=506,58, y=4,00, z=-2211,83], bsw['cedterminator'/1990, l='MpServer', x=630,81, y=11,34, z=-2107,69], bsw['gabrielitos'/2181, l='MpServer', x=633,69, y=4,16, z=-2111,53]]
	Chunk stats: MultiplayerChunkCache: 441, 441
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: 625,00,4,00,-2274,00 - World: (625,4,-2274), Chunk: (at 1,0,14 in 39,-143; contains blocks 624,0,-2288 to 639,255,-2273), Region: (1,-5; contains chunks 32,-160 to 63,-129, blocks 512,0,-2560 to 1023,255,-2049)
	Level time: 81192142 game time, 1000 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: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 20 total; [ub['entity.ItemFrame.name'/1, l='MpServer', x=514,50, y=5,50, z=-2263,97], ub['entity.ItemFrame.name'/2, l='MpServer', x=515,50, y=5,50, z=-2263,97], ub['entity.ItemFrame.name'/3, l='MpServer', x=518,50, y=5,50, z=-2263,97], ub['entity.ItemFrame.name'/4, l='MpServer', x=519,50, y=5,50, z=-2263,97], uj['Painting'/22, l='MpServer', x=671,97, y=10,50, z=-2267,00], bsw['gabrielitos'/2181, l='MpServer', x=633,69, y=4,16, z=-2111,53], bsw['gabrielitos'/2181, l='MpServer', x=545,41, y=4,00, z=-2553,78], uj['Painting'/19, l='MpServer', x=671,97, y=10,50, z=-2276,00], bsw['cedterminator'/1990, l='MpServer', x=630,81, y=11,34, z=-2107,69], bsw['cedterminator'/1990, l='MpServer', x=648,44, y=13,00, z=-2362,09], bsv['Zombiefighter331'/2299, l='MpServer', x=506,58, y=4,00, z=-2211,83], uj['Painting'/22, l='MpServer', x=671,97, y=10,50, z=-2267,00], bsw['cedterminator'/1990, l='MpServer', x=602,56, y=4,01, z=-2477,50], bsw['gabrielitos'/2181, l='MpServer', x=560,50, y=4,02, z=-2552,50], uj['Painting'/19, l='MpServer', x=671,97, y=10,50, z=-2276,00], bsw['cedterminator'/1990, l='MpServer', x=679,58, y=19,19, z=-2324,84], uj['Painting'/22, l='MpServer', x=671,97, y=10,50, z=-2267,00], bsw['cedterminator'/1990, l='MpServer', x=630,81, y=11,34, z=-2107,69], uj['Painting'/19, l='MpServer', x=671,97, y=10,50, z=-2276,00], bsw['gabrielitos'/2181, l='MpServer', x=633,69, y=4,16, z=-2111,53]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Non-integrated multiplayer server
Stacktrace:
	at bqr.a(SourceFile:308)
	at bfr.b(SourceFile:2069)
	at bfr.f(SourceFile:769)
	at net.minecraft.client.main.Main.main(SourceFile:121)

-- System Details --
Details:
	Minecraft Version: 14w11b
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_51, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 413934664 bytes (394 MB) / 597164032 bytes (569 MB) up to 954728448 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 14w11b
	LWJGL: 2.9.1
	OpenGL: GeForce GT 650M/PCIe/SSE2 GL version 4.2.0, NVIDIA Corporation
	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.
Anisotropic filtering is supported and maximum anisotropy is 16.
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: [Snapshot Sphax.zip]
	Current Language: English (UK)
	Profiler Position: N/A (disabled)
	Anisotropic Filtering: Off (1)

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-1464769/67530789/