Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at ny.a(SourceFile:89)
	at ou.aL(SourceFile:396)
	at ou.z(SourceFile:222)
	at ov.z(SourceFile:128)
	at oc.o_(SourceFile:279)
	at ou.o_(SourceFile:1167)
	at ov.o_(SourceFile:169)
	at ud.o_(SourceFile:29)
	at un.o_(SourceFile:211)
	at act.a(SourceFile:1351)
	at act.g(SourceFile:1329)

---- Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 9/5/13 2:34 PM
Description: Ticking entity

java.lang.NullPointerException
	at ny.a(SourceFile:89)
	at ou.aL(SourceFile:396)
	at ou.z(SourceFile:222)
	at ov.z(SourceFile:128)
	at oc.o_(SourceFile:279)
	at ou.o_(SourceFile:1167)
	at ov.o_(SourceFile:169)
	at ud.o_(SourceFile:29)
	at un.o_(SourceFile:211)
	at act.a(SourceFile:1351)
	at act.g(SourceFile:1329)
	at act.h(SourceFile:1236)
	at avx.m(SourceFile:1426)
	at avx.V(SourceFile:686)
	at avx.e(SourceFile:642)
	at net.minecraft.client.main.Main.main(SourceFile:103)


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

-- Head --
Stacktrace:
	at ny.a(SourceFile:89)
	at ou.aL(SourceFile:396)
	at ou.z(SourceFile:222)
	at ov.z(SourceFile:128)
	at oc.o_(SourceFile:279)
	at ou.o_(SourceFile:1167)
	at ov.o_(SourceFile:169)
	at ud.o_(SourceFile:29)
	at un.o_(SourceFile:211)
	at act.a(SourceFile:1351)
	at act.g(SourceFile:1329)

-- Entity being ticked --
Details:
	Entity Type: Zombie (un)
	Entity ID: 23827
	Entity Name: Supa' Ghost
	Entity's Exact location: -1499.50, 16.50, 1780.50
	Entity's Block location: World: (-1500,16,1780), Chunk: (at 4,1,4 in -94,111; contains blocks -1504,0,1776 to -1489,255,1791), Region: (-3,3; contains chunks -96,96 to -65,127, blocks -1536,0,1536 to -1025,255,2047)
	Entity's Momentum: 0.00, 0.00, 0.00
Stacktrace:
	at act.h(SourceFile:1236)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bfg['Gundrust'/10, l='MpServer', x=-1506.31, y=17.62, z=1788.29]]
	Chunk stats: MultiplayerChunkCache: 318, 318
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-1540,4,1799), Chunk: (at 12,0,7 in -97,112; contains blocks -1552,0,1792 to -1537,255,1807), Region: (-4,3; contains chunks -128,96 to -97,127, blocks -2048,0,1536 to -1537,255,2047)
	Level time: 194256 game time, 1169 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: 10 total; [uy['arrow'/0, l='MpServer', x=-1499.50, y=15.03, z=1800.50], uy['arrow'/1, l='MpServer', x=-1499.50, y=15.97, z=1800.50], sf['Chicken'/2, l='MpServer', x=-1474.38, y=16.00, z=1715.41], sf['Chicken'/4, l='MpServer', x=-1476.47, y=16.00, z=1724.53], op['Experience Orb'/23095, l='MpServer', x=-1506.91, y=16.25, z=1773.56], sf['Chicken'/5, l='MpServer', x=-1465.47, y=16.00, z=1718.44], sf['Chicken'/9, l='MpServer', x=-1463.38, y=16.00, z=1714.63], tj['item.item.egg'/23389, l='MpServer', x=-1474.72, y=16.13, z=1724.22], bfg['Gundrust'/10, l='MpServer', x=-1506.31, y=17.62, z=1788.29], un['Supa' Ghost'/23827, l='MpServer', x=-1499.50, y=16.50, z=1780.50]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bfb.a(SourceFile:285)
	at avx.b(SourceFile:1813)
	at avx.e(SourceFile:651)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w36a
	Operating System: Mac OS X (x86_64) version 10.7.5
	Java Version: 1.6.0_51, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 108276408 bytes (103 MB) / 279289856 bytes (266 MB) up to 1065025536 bytes (1015 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 112 (6272 bytes; 0 MB) allocated, 95 (5320 bytes; 0 MB) used
	Suspicious classes: [com.ibm.icu.text.ArabicShapingException], [gnu.trove.TIntCollection], [gnu.trove.impl.HashFunctions, PrimeFinder], [gnu.trove.impl.hash.THash, TPrimitiveHash, TIntIntHash], [gnu.trove.iterator.TIterator, TAdvancingIterator, TIntIntIterator], [gnu.trove.map.TIntIntMap], [gnu.trove.map.hash.TIntIntHashMap], [gnu.trove.procedure.TIntIntProcedure], [gnu.trove.set.TIntSet]
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 13w36a
	LWJGL: 2.9.0
	OpenGL: AMD Radeon HD 6770M OpenGL Engine GL version 2.1 ATI-7.32.12, ATI Technologies Inc.
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: [Pixel_Reality_-_Luminance_V1.0.zip]
	Current Language: English (US)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 78 (4368 bytes; 0 MB) allocated, 31 (1736 bytes; 0 MB) used