Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at nj.a(SourceFile:89)
	at of.aJ(SourceFile:384)
	at of.y(SourceFile:214)
	at og.y(SourceFile:128)
	at nn.l_(SourceFile:278)
	at of.l_(SourceFile:1149)
	at og.l_(SourceFile:169)
	at abw.a(SourceFile:1349)
	at js.a(SourceFile:479)
	at abw.g(SourceFile:1327)

---- Minecraft Crash Report ----
// Don't do that.

Time: 20.09.13 15:39
Description: Ticking entity

java.lang.NullPointerException
	at nj.a(SourceFile:89)
	at of.aJ(SourceFile:384)
	at of.y(SourceFile:214)
	at og.y(SourceFile:128)
	at nn.l_(SourceFile:278)
	at of.l_(SourceFile:1149)
	at og.l_(SourceFile:169)
	at abw.a(SourceFile:1349)
	at js.a(SourceFile:479)
	at abw.g(SourceFile:1327)
	at abw.h(SourceFile:1234)
	at js.h(SourceFile:364)
	at net.minecraft.server.MinecraftServer.t(SourceFile:471)
	at net.minecraft.server.MinecraftServer.s(SourceFile:406)
	at bkz.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:340)
	at hi.run(SourceFile:583)


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

-- Head --
Stacktrace:
	at nj.a(SourceFile:89)
	at of.aJ(SourceFile:384)
	at of.y(SourceFile:214)
	at og.y(SourceFile:128)
	at nn.l_(SourceFile:278)
	at of.l_(SourceFile:1149)
	at og.l_(SourceFile:169)
	at abw.a(SourceFile:1349)
	at js.a(SourceFile:479)
	at abw.g(SourceFile:1327)

-- Entity being ticked --
Details:
	Entity Type: Pig (ry)
	Entity ID: 278
	Entity Name: Pig
	Entity's Exact location: 2,32, 136,34, 258,60
	Entity's Block location: World: (2,136,258), Chunk: (at 2,8,2 in 0,16; contains blocks 0,0,256 to 15,255,271), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Entity's Momentum: 0,00, 0,00, 0,00
Stacktrace:
	at abw.h(SourceFile:1234)
	at js.h(SourceFile:364)

-- Affected level --
Details:
	Level name: New World
	All players: 1 total; [jv['minelp11'/219, l='New World', x=143,22, y=64,49, z=146,28]]
	Chunk stats: ServerChunkCache: 730 Drop: 0
	Level seed: 6965258645613721337
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: World: (248,64,132), Chunk: (at 8,4,4 in 15,8; contains blocks 240,0,128 to 255,255,143), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 50983 game time, 50983 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 1605 (now: false), thunder time: 69846 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.t(SourceFile:471)
	at net.minecraft.server.MinecraftServer.s(SourceFile:406)
	at bkz.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:340)
	at hi.run(SourceFile:583)

-- System Details --
Details:
	Minecraft Version: 1.6.4
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 127764808 bytes (121 MB) / 243990528 bytes (232 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 2884 (161504 bytes; 0 MB) allocated, 2884 (161504 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 1, tallocated: 63
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 895 (50120 bytes; 0 MB) allocated, 895 (50120 bytes; 0 MB) used
	Player Count: 1 / 8; [jv['minelp11'/219, l='New World', x=143,22, y=64,49, z=146,28]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.