Hopper: java.lang.ArrayIndexOutOfBoundsException: -1

java.lang.ArrayIndexOutOfBoundsException: -1
	at acv.a(SourceFile:168)
	at act.<init>(SourceFile:30)
	at acs.a(SourceFile:59)
	at acs.e(SourceFile:98)
	at acv.a(SourceFile:161)
	at acv.b(SourceFile:151)
	at aet.d(SourceFile:214)

---- Minecraft Crash Report ----
// Ooh. Shiny.

Time: 9/22/13 6:18 PM
Description: Exception generating new chunk

java.lang.ArrayIndexOutOfBoundsException: -1
	at acv.a(SourceFile:168)
	at act.<init>(SourceFile:30)
	at acs.a(SourceFile:59)
	at acs.e(SourceFile:98)
	at acv.a(SourceFile:161)
	at acv.b(SourceFile:151)
	at aet.d(SourceFile:214)
	at jr.c(SourceFile:84)
	at jr.d(SourceFile:116)
	at abw.e(SourceFile:289)
	at abw.a(SourceFile:213)
	at acj.b(SourceFile:84)
	at acj.a(SourceFile:49)
	at hn.a(SourceFile:422)
	at hn.a(SourceFile:352)
	at jv.b(SourceFile:296)
	at nn.y(SourceFile:315)
	at of.y(SourceFile:163)
	at nn.l_(SourceFile:278)
	at of.l_(SourceFile:1149)
	at uf.l_(SourceFile:203)
	at jv.h(SourceFile:185)
	at ka.a(SourceFile:190)
	at eu.a(SourceFile:136)
	at cn.b(SourceFile:64)
	at ka.e(SourceFile:60)
	at kd.b(SourceFile:37)
	at blc.b(SourceFile:84)
	at net.minecraft.server.MinecraftServer.t(SourceFile:489)
	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 acv.a(SourceFile:168)
	at act.<init>(SourceFile:30)
	at acs.a(SourceFile:59)
	at acs.e(SourceFile:98)
	at acv.a(SourceFile:161)
	at acv.b(SourceFile:151)
	at aet.d(SourceFile:214)

-- Chunk to be generated --
Details:
	Location: -26,-3
	Position hash: -8589934618
	Generator: RandomLevelSource
Stacktrace:
	at jr.c(SourceFile:84)
	at jr.d(SourceFile:116)
	at abw.e(SourceFile:289)

-- Requested block coordinates --
Details:
	Found chunk: true
	Location: World: (-402,255,-48), Chunk: (at 14,15,0 in -26,-3; contains blocks -416,0,-48 to -401,255,-33), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)
Stacktrace:
	at abw.a(SourceFile:213)
	at acj.b(SourceFile:84)
	at acj.a(SourceFile:49)
	at hn.a(SourceFile:422)
	at hn.a(SourceFile:352)
	at jv.b(SourceFile:296)
	at nn.y(SourceFile:315)
	at of.y(SourceFile:163)
	at nn.l_(SourceFile:278)
	at of.l_(SourceFile:1149)
	at uf.l_(SourceFile:203)

-- Player being ticked --
Details:
	Entity Type: null (jv)
	Entity ID: 103726
	Entity Name: jackyodinmortie
	Entity's Exact location: -274.00, 76.11, 67.00
	Entity's Block location: World: (-274,76,67), Chunk: (at 14,4,3 in -18,4; contains blocks -288,0,64 to -273,255,79), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Entity's Momentum: 0.00, 0.00, 0.00
Stacktrace:
	at jv.h(SourceFile:185)
	at ka.a(SourceFile:190)
	at eu.a(SourceFile:136)
	at cn.b(SourceFile:64)
	at ka.e(SourceFile:60)

-- Ticking connection --
Details:
	Connection: ka@acf7a2
Stacktrace:
	at kd.b(SourceFile:37)
	at blc.b(SourceFile:84)
	at net.minecraft.server.MinecraftServer.t(SourceFile:489)
	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 (x86) version 6.1
	Java Version: 1.7.0, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 276871744 bytes (264 MB) / 476028928 bytes (453 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 2049 (114744 bytes; 0 MB) allocated, 1829 (102424 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 14, allocated: 3, tallocated: 63
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [jv['jackyodinmortie'/103726, l='New World', x=-274.00, y=76.11, z=67.00]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.