Nether entering crash

---- Minecraft Crash Report ----
// You should try our sister game, Minceraft!

Time: 20.09.13 18:50
Description: Exception generating new chunk

java.lang.NullPointerException
	at agj.b(SourceFile:170)
	at agj.d(SourceFile:200)
	at km.c(SourceFile:72)
	at km.d(SourceFile:104)
	at ade.e(SourceFile:293)
	at ade.a(SourceFile:233)
	at ads.b(SourceFile:85)
	at ads.a(SourceFile:50)
	at jh.a(SourceFile:438)
	at jh.a(SourceFile:368)
	at kq.b(SourceFile:353)
	at om.B(SourceFile:321)
	at pe.B(SourceFile:165)
	at om.h(SourceFile:284)
	at pe.h(SourceFile:1159)
	at vg.h(SourceFile:205)
	at kq.i(SourceFile:198)
	at kv.a(SourceFile:196)
	at gn.a(SourceFile:136)
	at eb.b(SourceFile:63)
	at kv.e(SourceFile:64)
	at ky.b(SourceFile:37)
	at bow.b(SourceFile:83)
	at net.minecraft.server.MinecraftServer.u(SourceFile:487)
	at net.minecraft.server.MinecraftServer.t(SourceFile:404)
	at bot.t(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:338)
	at jc.run(SourceFile:581)


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

-- Head --
Stacktrace:
	at agj.b(SourceFile:170)
	at agj.d(SourceFile:200)

-- Chunk to be generated --
Details:
	Location: 1,-5
	Position hash: -21474836479
	Generator: HellRandomLevelSource
Stacktrace:
	at km.c(SourceFile:72)
	at km.d(SourceFile:104)
	at ade.e(SourceFile:293)

-- Requested block coordinates --
Details:
	Found chunk: true
	Location: World: (16,127,-80), Chunk: (at 0,7,0 in 1,-5; contains blocks 16,0,-80 to 31,255,-65), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
Stacktrace:
	at ade.a(SourceFile:233)
	at ads.b(SourceFile:85)
	at ads.a(SourceFile:50)
	at jh.a(SourceFile:438)
	at jh.a(SourceFile:368)
	at kq.b(SourceFile:353)
	at om.B(SourceFile:321)
	at pe.B(SourceFile:165)
	at om.h(SourceFile:284)
	at pe.h(SourceFile:1159)
	at vg.h(SourceFile:205)

-- Player being ticked --
Details:
	Entity Type: null (kq)
	Entity ID: 75
	Entity Name: Filter62
	Entity's Exact location: 6,00, 83,77, 32,00
	Entity's Block location: World: (6,83,32), Chunk: (at 6,5,0 in 0,2; contains blocks 0,0,32 to 15,255,47), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Entity's Momentum: 0,00, -0,23, 0,00
Stacktrace:
	at kq.i(SourceFile:198)
	at kv.a(SourceFile:196)
	at gn.a(SourceFile:136)
	at eb.b(SourceFile:63)
	at kv.e(SourceFile:64)

-- Ticking connection --
Details:
	Connection: kv@58d3ee56
Stacktrace:
	at ky.b(SourceFile:37)
	at bow.b(SourceFile:83)
	at net.minecraft.server.MinecraftServer.u(SourceFile:487)
	at net.minecraft.server.MinecraftServer.t(SourceFile:404)
	at bot.t(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:338)
	at jc.run(SourceFile:581)

-- System Details --
Details:
	Minecraft Version: 13w38b
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_40, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 229011152 bytes (218 MB) / 368574464 bytes (351 MB) up to 954728448 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 5025 (281400 bytes; 0 MB) allocated, 2427 (135912 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 852 (47712 bytes; 0 MB) allocated, 803 (44968 bytes; 0 MB) used
	Player Count: 1 / 8; [kq['Filter62'/75, l='Новый мир', x=6,00, y=83,77, z=32,00]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.