Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at ij.a(SourceFile:584)
	at ij.a(SourceFile:537)
	at aa.b(SourceFile:124)
	at net.minecraft.server.MinecraftServer.a(SourceFile:705)
	at jz.a(SourceFile:756)
	at dk.a(SourceFile:33)
	at cm.b(SourceFile:64)
	at jz.e(SourceFile:60)

---- Minecraft Crash Report ----
// I feel sad now :(

Time: 10.09.13 13:37
Description: Ticking memory connection

java.lang.NullPointerException
	at ij.a(SourceFile:584)
	at ij.a(SourceFile:537)
	at aa.b(SourceFile:124)
	at net.minecraft.server.MinecraftServer.a(SourceFile:705)
	at jz.a(SourceFile:756)
	at dk.a(SourceFile:33)
	at cm.b(SourceFile:64)
	at jz.e(SourceFile:60)
	at kc.b(SourceFile:37)
	at bkz.b(SourceFile:84)
	at net.minecraft.server.MinecraftServer.t(SourceFile:488)
	at net.minecraft.server.MinecraftServer.s(SourceFile:405)
	at bkw.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:339)
	at hh.run(SourceFile:582)


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

-- Head --
Stacktrace:
	at ij.a(SourceFile:584)
	at ij.a(SourceFile:537)
	at aa.b(SourceFile:124)
	at net.minecraft.server.MinecraftServer.a(SourceFile:705)
	at jz.a(SourceFile:756)
	at dk.a(SourceFile:33)
	at cm.b(SourceFile:64)
	at jz.e(SourceFile:60)

-- Ticking connection --
Details:
	Connection: jz@1028795
Stacktrace:
	at kc.b(SourceFile:37)
	at bkz.b(SourceFile:84)
	at net.minecraft.server.MinecraftServer.t(SourceFile:488)
	at net.minecraft.server.MinecraftServer.s(SourceFile:405)
	at bkw.s(SourceFile:124)
	at net.minecraft.server.MinecraftServer.run(SourceFile:339)
	at hh.run(SourceFile:582)

-- System Details --
Details:
	Minecraft Version: 1.6.2
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_13, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 105427792 bytes (100 MB) / 250929152 bytes (239 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 4549 (254744 bytes; 0 MB) allocated, 4287 (240072 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 1, tcache: 0, allocated: 1, tallocated: 63
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 1125 (63000 bytes; 0 MB) allocated, 1056 (59136 bytes; 0 MB) used
	Player Count: 1 / 8; [ju['homosapiens123'/310, l='Nananananananana SNAPSHOT!', x=25,79, y=65,62, z=245,13]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.