Hopper: java.lang.NullPointerException: Exception ticking world

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-467438/

Crash:

java.lang.NullPointerException: Exception ticking world
	at aga.a(SourceFile:72)
	at mj.b(SourceFile:117)

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

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

Time: 10/26/13 1:00 AM
Description: Exception ticking world

java.lang.NullPointerException: Exception ticking world
	at aga.a(SourceFile:72)
	at mj.b(SourceFile:117)
	at net.minecraft.server.MinecraftServer.u(SourceFile:503)
	at net.minecraft.server.MinecraftServer.t(SourceFile:441)
	at bsk.t(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:358)
	at ky.run(SourceFile:617)


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

-- Head --
Stacktrace:
	at aga.a(SourceFile:72)
	at mj.b(SourceFile:117)

-- Affected level --
Details:
	Level name: maze
	All players: 1 total; [mm['Paskalso'/62, l='maze', x=500.54, y=77.44, z=-246.20]]
	Chunk stats: ServerChunkCache: 1074 Drop: 0
	Level seed: -7822705456260230042
	Level generator: ID 01 - flat, ver 0. Features enabled: true
	Level generator options: 2;7,59x1,3x3,2;1;stronghold,biome_1,village,decoration,dungeon,lake,mineshaft,lava_lake
	Level spawn location: World: (-252,4,92), Chunk: (at 4,0,12 in -16,5; contains blocks -256,0,80 to -241,255,95), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 526733 game time, 124845 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 77644 (now: false), thunder time: 20601 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.u(SourceFile:503)
	at net.minecraft.server.MinecraftServer.t(SourceFile:441)
	at bsk.t(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:358)
	at ky.run(SourceFile:617)

-- System Details --
Details:
	Minecraft Version: 1.7.2
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.6.0_16, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Sun Microsystems Inc.
	Memory: 57892808 bytes (55 MB) / 384434176 bytes (366 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 1922 (107632 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 726 (40656 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Player Count: 1 / 8; [mm['Paskalso'/62, l='maze', x=500.54, y=77.44, z=-246.20]]
	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-467438/21676050/