Hopper: java.lang.NullPointerException 13w36a

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-72087/

Crash:

java.lang.NullPointerException
	at cx.b(SourceFile:116)
	at cx.a(SourceFile:41)

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

---- Minecraft Crash Report ----
// I let you down. Sorry :(

Time: 5/09/13 16:00
Description: Sending packet

java.lang.NullPointerException
	at cx.b(SourceFile:116)
	at cx.a(SourceFile:41)
	at kl.b(SourceFile:430)
	at le.b(SourceFile:170)
	at hx.a(SourceFile:86)
	at bnj.b(SourceFile:73)
	at net.minecraft.server.MinecraftServer.t(SourceFile:481)
	at net.minecraft.server.MinecraftServer.s(SourceFile:398)
	at bng.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hs.run(SourceFile:575)


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

-- Head --
Stacktrace:
	at cx.b(SourceFile:116)
	at cx.a(SourceFile:41)

-- Packet being sent --
Details:
	Packet ID: 200
	Packet class: du
Stacktrace:
	at kl.b(SourceFile:430)
	at le.b(SourceFile:170)
	at hx.a(SourceFile:86)
	at bnj.b(SourceFile:73)
	at net.minecraft.server.MinecraftServer.t(SourceFile:481)
	at net.minecraft.server.MinecraftServer.s(SourceFile:398)
	at bng.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:332)
	at hs.run(SourceFile:575)

-- System Details --
Details:
	Minecraft Version: 13w36a
	Operating System: Mac OS X (x86_64) version 10.7.2
	Java Version: 1.6.0_35, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 64053656 bytes (61 MB) / 134057984 bytes (127 MB) up to 1065025536 bytes (1015 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 1141 (63896 bytes; 0 MB) allocated, 1141 (63896 bytes; 0 MB) used
	Suspicious classes: [com.ibm.icu.text.ArabicShapingException], [gnu.trove.TIntCollection], [gnu.trove.impl.HashFunctions, PrimeFinder], [gnu.trove.impl.hash.THash, TPrimitiveHash, TIntIntHash], [gnu.trove.iterator.TIterator, TAdvancingIterator, TIntIntIterator], [gnu.trove.map.TIntIntMap], [gnu.trove.map.hash.TIntIntHashMap], [gnu.trove.procedure.TIntIntProcedure], [gnu.trove.set.TIntSet]
	IntCache: cache: 13, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 134 (7504 bytes; 0 MB) allocated, 134 (7504 bytes; 0 MB) used
	Player Count: 0 / 8; []
	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-72087/8087825/