Hopper: java.lang.NullPointerException

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-293289/

Crash:

java.lang.NullPointerException
	at abj.g(SourceFile:151)
	at abj.i(SourceFile:171)

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

---- Minecraft Crash Report ----
// Shall we play a game?

Time: 10/10/13 9:48 AM
Description: Adding item to inventory

java.lang.NullPointerException
	at abj.g(SourceFile:151)
	at abj.i(SourceFile:171)
	at xd.a(SourceFile:234)
	at vq.b_(SourceFile:199)
	at xf.r(SourceFile:465)
	at xf.e(SourceFile:457)
	at rb.h(SourceFile:1196)
	at xf.h(SourceFile:240)
	at mi.i(SourceFile:207)
	at ms.a(SourceFile:201)
	at is.a(SourceFile:127)
	at is.a(SourceFile:8)
	at ek.a(SourceFile:150)
	at mo.c(SourceFile:134)
	at net.minecraft.server.MinecraftServer.u(SourceFile:528)
	at net.minecraft.server.MinecraftServer.t(SourceFile:440)
	at brh.t(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:358)
	at kw.run(SourceFile:616)


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

-- Head --
Stacktrace:
	at abj.g(SourceFile:151)
	at abj.i(SourceFile:171)

-- Item being added --
Details:
	Item ID: 0
	Item data: 0
	Item name: ~~ERROR~~ NullPointerException: null
Stacktrace:
	at xd.a(SourceFile:234)
	at vq.b_(SourceFile:199)
	at xf.r(SourceFile:465)
	at xf.e(SourceFile:457)
	at rb.h(SourceFile:1196)
	at xf.h(SourceFile:240)

-- Player being ticked --
Details:
	Entity Type: null (mi)
	Entity ID: 339
	Entity Name: OrthoLabs
	Entity's Exact location: -140.66, 209.12, 305.69
	Entity's Block location: World: (-141,209,305), Chunk: (at 3,13,1 in -9,19; contains blocks -144,0,304 to -129,255,319), 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 mi.i(SourceFile:207)
	at ms.a(SourceFile:201)
	at is.a(SourceFile:127)
	at is.a(SourceFile:8)
	at ek.a(SourceFile:150)

-- Ticking connection --
Details:
	Connection: ek@3144ca50
Stacktrace:
	at mo.c(SourceFile:134)
	at net.minecraft.server.MinecraftServer.u(SourceFile:528)
	at net.minecraft.server.MinecraftServer.t(SourceFile:440)
	at brh.t(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:358)
	at kw.run(SourceFile:616)

-- System Details --
Details:
	Minecraft Version: 13w41a
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 290070592 bytes (276 MB) / 525664256 bytes (501 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 2329 (130424 bytes; 0 MB) allocated, 2204 (123424 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 1545 (86520 bytes; 0 MB) allocated, 272 (15232 bytes; 0 MB) used
	Player Count: 1 / 8; [mi['OrthoLabs'/339, l='New World', x=-140.66, y=209.12, z=305.69]]
	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-293289/16535011/