Hopper: java.lang.NullPointerException: Unexpected error

java.lang.NullPointerException: Unexpected error
	at bin.a(SourceFile:481)
	at hc.a(SourceFile:47)
	at hc.a(SourceFile:12)
	at el.a(SourceFile:145)
	at biq.e(SourceFile:212)

---- Minecraft Crash Report ----
// This doesn't make any sense!

Time: 19.10.13 00:02
Description: Unexpected error

java.lang.NullPointerException: Unexpected error
	at bin.a(SourceFile:481)
	at hc.a(SourceFile:47)
	at hc.a(SourceFile:12)
	at el.a(SourceFile:145)
	at biq.e(SourceFile:212)
	at ayw.o(SourceFile:1280)
	at ayw.ad(SourceFile:755)
	at ayw.e(SourceFile:706)
	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 bin.a(SourceFile:481)
	at hc.a(SourceFile:47)
	at hc.a(SourceFile:12)
	at el.a(SourceFile:145)
	at biq.e(SourceFile:212)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [biw['Geissboeckchen'/955944, l='MpServer', x=-121,25, y=93,62, z=136,54]]
	Chunk stats: MultiplayerChunkCache: 271, 271
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (8,64,8), Chunk: (at 8,4,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 36158937 game time, 36876544 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: 76 total; [un['Bat'/983766, l='MpServer', x=-185,97, y=25,00, z=98,25], un['Bat'/983887, l='MpServer', x=-183,38, y=22,34, z=105,03], un['Bat'/983765, l='MpServer', x=-186,13, y=22,46, z=101,75], wu['Skeleton'/985674, l='MpServer', x=-191,50, y=23,00, z=139,50], wu['Skeleton'/985675, l='MpServer', x=-194,50, y=23,00, z=141,50], un['Bat'/984365, l='MpServer', x=-162,75, y=27,00, z=129,75], wi['Creeper'/984846, l='MpServer', x=-191,50, y=21,00, z=127,50], wz['Zombie'/984847, l='MpServer', x=-190,50, y=21,00, z=126,50], wi['Creeper'/983144, l='MpServer', x=-134,50, y=53,00, z=161,50], wz['Zombie'/983145, l='MpServer', x=-136,50, y=53,00, z=158,50], wu['Skeleton'/985211, l='MpServer', x=-147,50, y=49,00, z=142,50], xl['arrow'/333326, l='MpServer', x=-106,75, y=87,97, z=161,53], un['Bat'/984383, l='MpServer', x=-64,28, y=34,07, z=132,94], un['Bat'/984382, l='MpServer', x=-60,31, y=37,85, z=134,75], wz['Zombie'/984861, l='MpServer', x=-187,50, y=23,00, z=98,50], wi['Creeper'/983142, l='MpServer', x=-135,50, y=53,00, z=156,50], wi['Creeper'/983143, l='MpServer', x=-135,50, y=53,00, z=161,50], un['Bat'/984087, l='MpServer', x=-170,50, y=30,07, z=111,53], wu['Skeleton'/985710, l='MpServer', x=-177,50, y=38,00, z=123,50], wz['Zombie'/985711, l='MpServer', x=-179,50, y=38,00, z=125,50], wi['Creeper'/985704, l='MpServer', x=-60,50, y=39,00, z=141,50], wi['Creeper'/985705, l='MpServer', x=-60,50, y=39,00, z=140,50], wi['Creeper'/985702, l='MpServer', x=-57,50, y=39,00, z=142,50], wi['Creeper'/985703, l='MpServer', x=-57,50, y=39,00, z=141,50], wi['Creeper'/984207, l='MpServer', x=-185,28, y=40,00, z=144,03], wi['Creeper'/984206, l='MpServer', x=-185,50, y=39,00, z=141,50], wi['Creeper'/984205, l='MpServer', x=-186,50, y=39,00, z=140,50], wy['Witch'/984204, l='MpServer', x=-180,50, y=39,00, z=138,50], wu['Skeleton'/984076, l='MpServer', x=-83,50, y=34,00, z=153,50], wu['Skeleton'/984077, l='MpServer', x=-84,50, y=34,00, z=153,50], wu['Skeleton'/985712, l='MpServer', x=-188,50, y=56,00, z=209,50], wz['Zombie'/984662, l='MpServer', x=-57,50, y=31,00, z=62,50], wz['Zombie'/984422, l='MpServer', x=-60,50, y=31,00, z=74,50], wz['Zombie'/984423, l='MpServer', x=-58,50, y=31,00, z=72,50], wi['Creeper'/984546, l='MpServer', x=-143,50, y=50,00, z=170,50], biw['Geissboeckchen'/955944, l='MpServer', x=-121,25, y=93,62, z=136,54], wz['Zombie'/984424, l='MpServer', x=-60,50, y=31,00, z=75,50], wz['Zombie'/984545, l='MpServer', x=-144,50, y=50,00, z=170,50], bkv['thamma'/955132, l='MpServer', x=-122,00, y=92,50, z=133,00], un['Bat'/983814, l='MpServer', x=-132,78, y=52,27, z=165,56], wz['Zombie'/985625, l='MpServer', x=-167,50, y=27,00, z=126,50], wu['Skeleton'/985624, l='MpServer', x=-167,50, y=27,00, z=123,50], wz['Zombie'/985049, l='MpServer', x=-76,50, y=29,00, z=119,50], wi['Creeper'/983957, l='MpServer', x=-169,50, y=23,00, z=127,50], wz['Zombie'/985050, l='MpServer', x=-77,50, y=29,00, z=119,50], wi['Creeper'/983958, l='MpServer', x=-169,50, y=23,00, z=125,50], wz['Zombie'/983959, l='MpServer', x=-168,50, y=23,00, z=128,50], wz['Zombie'/983960, l='MpServer', x=-172,50, y=23,00, z=127,50], wy['Witch'/983486, l='MpServer', x=-171,38, y=24,00, z=122,72], wi['Creeper'/983487, l='MpServer', x=-59,41, y=41,00, z=84,00], wz['Zombie'/984927, l='MpServer', x=-185,50, y=37,00, z=68,50], wz['Zombie'/984566, l='MpServer', x=-73,50, y=31,00, z=84,50], wz['Zombie'/984565, l='MpServer', x=-69,50, y=31,00, z=82,50], wu['Skeleton'/985102, l='MpServer', x=-86,50, y=26,00, z=83,50], un['Bat'/984384, l='MpServer', x=-59,75, y=38,26, z=125,25], wu['Skeleton'/985103, l='MpServer', x=-80,50, y=26,00, z=78,50], un['Bat'/984385, l='MpServer', x=-59,63, y=36,07, z=130,25], wz['Zombie'/983431, l='MpServer', x=-200,50, y=14,00, z=86,50], un['Bat'/983186, l='MpServer', x=-176,78, y=30,00, z=161,56], wz['Zombie'/985645, l='MpServer', x=-67,50, y=34,00, z=133,50], wz['Zombie'/984690, l='MpServer', x=-185,50, y=41,00, z=109,50], ww['Spider'/984942, l='MpServer', x=-73,50, y=23,00, z=121,50], wz['Zombie'/984820, l='MpServer', x=-175,50, y=29,00, z=113,00], wz['Zombie'/984821, l='MpServer', x=-172,31, y=29,00, z=112,53], wy['Witch'/984812, l='MpServer', x=-182,50, y=13,00, z=159,50], wz['Zombie'/984949, l='MpServer', x=-95,50, y=13,00, z=96,50], wz['Zombie'/984948, l='MpServer', x=-93,50, y=13,00, z=97,50], wz['Zombie'/983321, l='MpServer', x=-152,50, y=50,00, z=155,50], wz['Zombie'/983322, l='MpServer', x=-153,50, y=50,00, z=154,50], wu['Skeleton'/983317, l='MpServer', x=-65,50, y=31,00, z=80,50], wi['Creeper'/984139, l='MpServer', x=-176,50, y=24,00, z=115,50], wi['Creeper'/983319, l='MpServer', x=-153,50, y=50,00, z=153,50], wj['Enderman'/983318, l='MpServer', x=-61,69, y=31,00, z=76,31], wu['Skeleton'/985240, l='MpServer', x=-52,50, y=37,00, z=123,50], wu['Skeleton'/985105, l='MpServer', x=-84,50, y=26,00, z=82,50], wu['Skeleton'/985104, l='MpServer', x=-81,97, y=26,00, z=80,41]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Non-integrated multiplayer server
Stacktrace:
	at bir.a(SourceFile:284)
	at ayw.b(SourceFile:1938)
	at ayw.e(SourceFile:720)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w42b
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_21, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 115779224 bytes (110 MB) / 306708480 bytes (292 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 17304 (969024 bytes; 0 MB) allocated, 2 (112 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Launched Version: 13w42b
	LWJGL: 2.9.0
	OpenGL: GeForce GTX 570/PCI/SSE2 GL version 4.1.0, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: []
	Current Language: English (UK)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 616 (34496 bytes; 0 MB) allocated, 20 (1120 bytes; 0 MB) used
	Anisotropic Filtering: Off (1)