Minecraft launcher crashes when game starts up

Please attach the crash report, otherwise this ticket is incomplete.

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

Time: 5/9/13 5:51 PM
Description: Sending packet

java.lang.NullPointerException
	at ch.b(SourceFile:107)
	at ch.a(SourceFile:39)
	at jh.b(SourceFile:430)
	at gu.b(SourceFile:669)
	at gu.a(SourceFile:79)
	at bjj.b(SourceFile:73)
	at net.minecraft.server.MinecraftServer.r(SourceFile:480)
	at net.minecraft.server.MinecraftServer.q(SourceFile:397)
	at bjg.q(SourceFile:122)
	at net.minecraft.server.MinecraftServer.run(SourceFile:331)
	at gp.run(SourceFile:573)


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

-- Head --
Stacktrace:
	at ch.b(SourceFile:107)
	at ch.a(SourceFile:39)

-- Packet being sent --
Details:
	Packet ID: 4
	Packet class: fh
Stacktrace:
	at jh.b(SourceFile:430)
	at gu.b(SourceFile:669)
	at gu.a(SourceFile:79)
	at bjj.b(SourceFile:73)
	at net.minecraft.server.MinecraftServer.r(SourceFile:480)
	at net.minecraft.server.MinecraftServer.q(SourceFile:397)
	at bjg.q(SourceFile:122)
	at net.minecraft.server.MinecraftServer.run(SourceFile:331)
	at gp.run(SourceFile:573)

-- System Details --
Details:
	Minecraft Version: 1.5.2
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.6.0_31, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Sun Microsystems Inc.
	Memory: 283728104 bytes (270 MB) / 891260928 bytes (849 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -Xms512m -Xmx1024m

Duplicate of MC-3766.

So what's the damage, doc? I've had a lot of fun with that world, and you'd have my gratitude if you could provide a cure for this disease.

World corruption. You might want to take a look here: http://www.minecraftforum.net/topic/137381-official-corrupted-save-recovery-thread/