Hopper: java.lang.ArrayIndexOutOfBoundsException: -1 (Crash on exit)

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-1194699/

Crash:

java.lang.ArrayIndexOutOfBoundsException: -1
	at java.util.ArrayList.fastRemove(Unknown Source)
	at java.util.ArrayList.remove(Unknown Source)
	at ns.b(SourceFile:62)
	at nr.c(SourceFile:328)
	at mo.e(SourceFile:242)
	at oi.a(SourceFile:450)
	at od.c(SourceFile:130)
	at net.minecraft.server.MinecraftServer.v(SourceFile:545)
	at net.minecraft.server.MinecraftServer.u(SourceFile:461)
	at cbr.u(SourceFile:125)
	at net.minecraft.server.MinecraftServer.run(SourceFile:377)
	at mk.run(SourceFile:647)

The following is the first clean report made public about this crash:

---- Minecraft Crash Report ----
// You're mean.

Time: 2/6/14 10:25 AM
Description: Exception in server tick loop

java.lang.ArrayIndexOutOfBoundsException: -1
	at java.util.ArrayList.fastRemove(Unknown Source)
	at java.util.ArrayList.remove(Unknown Source)
	at ns.b(SourceFile:62)
	at nr.c(SourceFile:328)
	at mo.e(SourceFile:242)
	at oi.a(SourceFile:450)
	at od.c(SourceFile:130)
	at net.minecraft.server.MinecraftServer.v(SourceFile:545)
	at net.minecraft.server.MinecraftServer.u(SourceFile:461)
	at cbr.u(SourceFile:125)
	at net.minecraft.server.MinecraftServer.run(SourceFile:377)
	at mk.run(SourceFile:647)


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

-- System Details --
Details:
	Minecraft Version: 14w06b
	Operating System: Windows 8 (amd64) version 6.2
	Java Version: 1.7.0_45, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 82233752 bytes (78 MB) / 458752000 bytes (437 MB) up to 954728448 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [nx['kingcap'/0, l='Dark Souls', x=-812.50, y=4.00, z=-1200.08]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-1194699/57468968/