Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at awy.a(SourceFile:441)
	at awe.d(SourceFile:135)
	at awe.m(SourceFile:107)

---- Minecraft Crash Report ----
// Oops.

Time: 19.09.13 19:02
Description: Updating screen events

java.lang.NullPointerException
	at awy.a(SourceFile:441)
	at awe.d(SourceFile:135)
	at awe.m(SourceFile:107)
	at atv.k(SourceFile:1158)
	at atv.S(SourceFile:663)
	at atv.d(SourceFile:619)
	at net.minecraft.client.main.Main.main(SourceFile:101)


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

-- Head --
Stacktrace:
	at awy.a(SourceFile:441)
	at awe.d(SourceFile:135)
	at awe.m(SourceFile:107)

-- Affected screen --
Details:
	Screen name: axj

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bdi['Elija1'/11568, l='MpServer', x=281,87, y=58,62, z=-9,27]]
	Chunk stats: MultiplayerChunkCache: 441
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (244,64,-40), Chunk: (at 4,4,8 in 15,-3; contains blocks 240,0,-48 to 255,255,-33), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Level time: 873936 game time, 908707 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: survival (ID 0). Hardcore: false. Cheats: false
	Forced entities: 95 total; [tf['Creeper'/58357, l='MpServer', x=207,50, y=64,00, z=-57,50], tw['Zombie'/58527, l='MpServer', x=319,50, y=63,00, z=9,50], tr['Skelett'/57555, l='MpServer', x=258,50, y=64,00, z=31,50], tt['Spinne'/58523, l='MpServer', x=315,47, y=63,00, z=8,94], tr['Skelett'/58337, l='MpServer', x=285,50, y=58,00, z=24,50], tr['Skelett'/57556, l='MpServer', x=249,50, y=62,12, z=16,53], tw['Zombie'/58350, l='MpServer', x=207,50, y=64,00, z=-62,50], tw['Zombie'/57563, l='MpServer', x=348,50, y=13,00, z=-29,50], tt['Spinne'/58348, l='MpServer', x=282,41, y=28,06, z=-80,72], tf['Creeper'/58346, l='MpServer', x=284,50, y=27,00, z=-80,50], tt['Spinne'/58345, l='MpServer', x=311,53, y=63,00, z=38,06], tr['Skelett'/57565, l='MpServer', x=229,94, y=12,00, z=0,44], tt['Spinne'/57189, l='MpServer', x=272,81, y=65,00, z=63,63], tr['Skelett'/58529, l='MpServer', x=316,50, y=35,00, z=3,50], tf['Creeper'/58528, l='MpServer', x=316,50, y=35,00, z=1,50], tf['Creeper'/57204, l='MpServer', x=336,50, y=25,00, z=-43,50], tf['Creeper'/57203, l='MpServer', x=338,50, y=25,00, z=-44,50], ss['item.tile.sand'/54920, l='MpServer', x=292,28, y=59,13, z=-11,22], ro['Fledermaus'/58841, l='MpServer', x=216,75, y=40,10, z=5,44], ro['Fledermaus'/55901, l='MpServer', x=259,75, y=47,10, z=-8,59], ss['item.tile.sand'/54921, l='MpServer', x=292,66, y=59,13, z=-11,97], ro['Fledermaus'/58842, l='MpServer', x=246,48, y=47,21, z=9,75], ro['Fledermaus'/58843, l='MpServer', x=242,84, y=48,10, z=15,84], ro['Fledermaus'/58847, l='MpServer', x=282,75, y=27,10, z=-85,50], ss['item.tile.sand'/54914, l='MpServer', x=290,50, y=60,13, z=-11,19], ss['item.tile.sand'/54917, l='MpServer', x=295,78, y=59,13, z=-13,16], ss['item.tile.sand'/54918, l='MpServer', x=292,13, y=60,13, z=-15,78], tf['Creeper'/57112, l='MpServer', x=281,09, y=64,00, z=-57,72], ss['item.item.dyePowder.black'/50562, l='MpServer', x=250,63, y=50,13, z=-10,16], tf['Creeper'/55916, l='MpServer', x=239,31, y=14,00, z=22,75], ss['item.tile.sand'/56322, l='MpServer', x=286,28, y=62,13, z=-14,72], ro['Fledermaus'/56181, l='MpServer', x=224,44, y=45,23, z=53,34], ro['Fledermaus'/56183, l='MpServer', x=223,50, y=45,07, z=57,91], ro['Fledermaus'/39930, l='MpServer', x=301,22, y=48,10, z=-37,22], tr['Skelett'/56815, l='MpServer', x=305,50, y=69,00, z=-81,50], tf['Creeper'/58933, l='MpServer', x=272,50, y=37,00, z=31,50], rz['Schaf'/11548, l='MpServer', x=263,22, y=68,00, z=-79,47], ro['Fledermaus'/56221, l='MpServer', x=334,47, y=13,98, z=-31,84], ss['item.tile.sand'/54887, l='MpServer', x=295,31, y=60,13, z=-14,84], sc['Tintenfisch'/57722, l='MpServer', x=340,66, y=59,34, z=-46,50], ss['item.tile.sand'/54886, l='MpServer', x=294,28, y=59,13, z=-14,31], sc['Tintenfisch'/57721, l='MpServer', x=334,13, y=57,69, z=-57,50], ss['item.tile.stonebrick'/54885, l='MpServer', x=292,81, y=59,13, z=-11,22], sc['Tintenfisch'/57720, l='MpServer', x=335,66, y=57,75, z=-53,53], ss['item.tile.pistonStickyBase'/54884, l='MpServer', x=294,13, y=59,13, z=-11,69], sc['Tintenfisch'/57727, l='MpServer', x=345,19, y=59,81, z=-71,06], ss['item.tile.pressurePlate'/54883, l='MpServer', x=292,06, y=59,13, z=-11,16], tf['Creeper'/56230, l='MpServer', x=289,50, y=19,00, z=-82,50], oa['Erfahrungskugel'/54895, l='MpServer', x=295,59, y=60,25, z=-14,22], ry['Schwein'/11555, l='MpServer', x=293,03, y=70,00, z=-69,84], ry['Schwein'/11552, l='MpServer', x=289,50, y=68,00, z=-66,75], oa['Erfahrungskugel'/54892, l='MpServer', x=290,25, y=59,25, z=-12,75], sc['Tintenfisch'/57719, l='MpServer', x=342,28, y=55,88, z=-45,19], oa['Erfahrungskugel'/54891, l='MpServer', x=290,25, y=59,25, z=-12,75], oa['Erfahrungskugel'/54890, l='MpServer', x=295,25, y=63,25, z=-10,78], oa['Erfahrungskugel'/54889, l='MpServer', x=296,09, y=60,25, z=-13,59], ss['item.item.diamond'/54888, l='MpServer', x=296,75, y=60,13, z=-12,47], ry['Schwein'/11557, l='MpServer', x=322,81, y=63,00, z=-78,50], ss['item.tile.sand'/54901, l='MpServer', x=293,19, y=59,13, z=-15,09], ro['Fledermaus'/57067, l='MpServer', x=342,91, y=25,00, z=-46,00], oa['Erfahrungskugel'/54896, l='MpServer', x=295,91, y=60,25, z=-13,66], oa['Erfahrungskugel'/54897, l='MpServer', x=296,59, y=59,25, z=-11,34], ss['item.tile.pistonStickyBase'/54910, l='MpServer', x=292,84, y=61,13, z=-10,97], ss['item.tile.sand'/54911, l='MpServer', x=296,81, y=60,13, z=-13,84], ss['item.tile.sand'/54908, l='MpServer', x=294,69, y=59,13, z=-12,84], ss['item.tile.sand'/54909, l='MpServer', x=293,31, y=59,13, z=-13,88], oa['Erfahrungskugel'/54906, l='MpServer', x=294,44, y=59,25, z=-11,38], oa['Erfahrungskugel'/54907, l='MpServer', x=291,25, y=60,25, z=-13,81], ro['Fledermaus'/50541, l='MpServer', x=281,25, y=45,10, z=-40,25], ss['item.tile.sand'/54904, l='MpServer', x=291,31, y=61,13, z=-15,84], tw['Zombie'/57888, l='MpServer', x=249,50, y=46,00, z=-15,50], bdi['Elija1'/11568, l='MpServer', x=281,87, y=58,62, z=-9,27], tr['Skelett'/58739, l='MpServer', x=320,50, y=39,00, z=-76,50], tt['Spinne'/58736, l='MpServer', x=293,38, y=68,00, z=-75,78], tf['Creeper'/57660, l='MpServer', x=227,56, y=13,00, z=-17,97], tw['Zombie'/57016, l='MpServer', x=224,50, y=46,00, z=50,50], tw['Zombie'/52891, l='MpServer', x=298,03, y=60,00, z=-1,47], tf['Creeper'/58740, l='MpServer', x=322,50, y=39,00, z=-77,50], tf['Creeper'/56063, l='MpServer', x=296,00, y=37,00, z=1,44], tf['Creeper'/56061, l='MpServer', x=291,31, y=35,90, z=-13,88], tf['Creeper'/56060, l='MpServer', x=291,30, y=35,00, z=-14,68], tt['Spinne'/53317, l='MpServer', x=274,84, y=64,00, z=55,59], tw['Zombie'/55518, l='MpServer', x=277,82, y=59,52, z=-40,81], ss['item.tile.sandStone.default'/56311, l='MpServer', x=288,81, y=61,13, z=-14,69], ss['item.tile.sand'/56310, l='MpServer', x=288,69, y=61,13, z=-14,19], ss['item.tile.sand'/56305, l='MpServer', x=289,94, y=61,13, z=-12,72], tr['Skelett'/58727, l='MpServer', x=212,50, y=26,00, z=-12,50], tf['Creeper'/57886, l='MpServer', x=262,00, y=22,00, z=-22,63], ss['item.tile.sand'/56307, l='MpServer', x=285,56, y=62,13, z=-13,31], ss['item.tile.sand'/56317, l='MpServer', x=287,72, y=61,13, z=-11,19], ss['item.tile.sand'/56316, l='MpServer', x=290,00, y=62,13, z=-13,38], ss['item.tile.sand'/56319, l='MpServer', x=286,09, y=62,13, z=-11,19], ss['item.tile.sand'/56318, l='MpServer', x=285,38, y=62,13, z=-14,22], ss['item.tile.sand'/56315, l='MpServer', x=286,59, y=61,13, z=-13,81], ss['item.tile.sand'/56314, l='MpServer', x=285,88, y=62,13, z=-12,44]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bdd.a(SourceFile:284)
	at atv.b(SourceFile:1761)
	at atv.d(SourceFile:628)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.4
	Operating System: Mac OS X (x86_64) version 10.6.8
	Java Version: 1.6.0_51, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 53194208 bytes (50 MB) / 293937152 bytes (280 MB) up to 1069416448 bytes (1019 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 2625 (147000 bytes; 0 MB) allocated, 2 (112 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 1, tallocated: 63
	Launched Version: 1.6.4
	LWJGL: 2.9.0
	OpenGL: NVIDIA GeForce 9400 OpenGL Engine GL version 2.1 NVIDIA-1.6.36, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Default
	Current Language: Deutsch (Deutschland)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 2165 (121240 bytes; 0 MB) allocated, 17 (952 bytes; 0 MB) used