Hopper: java.lang.NullPointerException: Ticking entity

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-242601/

Crash:

java.lang.NullPointerException
	at to.a(SourceFile:133)
	at to.k(SourceFile:120)
	at to.h(SourceFile:95)
	at ade.a(SourceFile:1361)
	at kn.a(SourceFile:477)
	at ade.g(SourceFile:1339)

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

---- Minecraft Crash Report ----
// This doesn't make any sense!

Time: 26/09/13 19:05
Description: Ticking entity

java.lang.NullPointerException
	at to.a(SourceFile:133)
	at to.k(SourceFile:120)
	at to.h(SourceFile:95)
	at ade.a(SourceFile:1361)
	at kn.a(SourceFile:477)
	at ade.g(SourceFile:1339)
	at ade.h(SourceFile:1246)
	at kn.h(SourceFile:362)
	at net.minecraft.server.MinecraftServer.u(SourceFile:476)
	at net.minecraft.server.MinecraftServer.t(SourceFile:411)
	at bos.t(SourceFile:121)
	at net.minecraft.server.MinecraftServer.run(SourceFile:346)
	at jc.run(SourceFile:582)


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

-- Head --
Stacktrace:
	at to.a(SourceFile:133)
	at to.k(SourceFile:120)
	at to.h(SourceFile:95)
	at ade.a(SourceFile:1361)
	at kn.a(SourceFile:477)
	at ade.g(SourceFile:1339)

-- Entity being ticked --
Details:
	Entity Type: Item (to)
	Entity ID: 32784
	Entity Name: ~~ERROR~~ NullPointerException: null
	Entity's Exact location: -56,20, 15,35, 454,53
	Entity's Block location: World: (-57,15,454), Chunk: (at 7,0,6 in -4,28; contains blocks -64,0,448 to -49,255,463), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Entity's Momentum: -0,23, 0,07, 0,01
Stacktrace:
	at ade.h(SourceFile:1246)
	at kn.h(SourceFile:362)

-- Affected level --
Details:
	Level name: test 1.7
	All players: 1 total; [kq['leogabrielplay'/4, l='test 1.7', x=-57,75, y=16,98, z=455,88]]
	Chunk stats: ServerChunkCache: 625 Drop: 0
	Level seed: -6528935923800851363
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 2;0;1;village
	Level spawn location: World: (-73,4,433), Chunk: (at 7,0,1 in -5,27; contains blocks -80,0,432 to -65,255,447), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 17459 game time, 17459 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 20882 (now: false), thunder time: 43864 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.u(SourceFile:476)
	at net.minecraft.server.MinecraftServer.t(SourceFile:411)
	at bos.t(SourceFile:121)
	at net.minecraft.server.MinecraftServer.run(SourceFile:346)
	at jc.run(SourceFile:582)

-- System Details --
Details:
	Minecraft Version: 13w39a
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 29659608 bytes (28 MB) / 131387392 bytes (125 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 823 (46088 bytes; 0 MB) allocated, 482 (26992 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 17 (952 bytes; 0 MB) allocated, 5 (280 bytes; 0 MB) used
	Player Count: 1 / 8; [kq['leogabrielplay'/4, l='test 1.7', x=-57,75, y=16,98, z=455,88]]
	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-242601/14402432/