Hopper: java.lang.IllegalStateException: Failed to add player. mp['Spyro12321'/29, l='Autumn Planarium', x=480.94, y=4.00, z=2062.92] already is in chunk 17,

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-772236/

Crash:

java.lang.IllegalStateException: Failed to add player. mp['Spyro12321'/29, l='Autumn Planarium', x=480.94, y=4.00, z=2062.92] already is in chunk 17, 116
	at mk.a(SourceFile:37)
	at mj.a(SourceFile:379)
	at lg.a(SourceFile:778)
	at bti.t(SourceFile:121)
	at net.minecraft.server.MinecraftServer.run(SourceFile:357)
	at lb.run(SourceFile:616)

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

---- Minecraft Crash Report ----
// Ouch. That hurt :(

Time: 05/12/13 14:49
Description: Exception in server tick loop

java.lang.IllegalStateException: Failed to add player. mp['Spyro12321'/29, l='Autumn Planarium', x=480.94, y=4.00, z=2062.92] already is in chunk 17, 116
	at mk.a(SourceFile:37)
	at mj.a(SourceFile:379)
	at lg.a(SourceFile:778)
	at bti.t(SourceFile:121)
	at net.minecraft.server.MinecraftServer.run(SourceFile:357)
	at lb.run(SourceFile:616)


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

-- System Details --
Details:
	Minecraft Version: 13w49a
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_13, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 299567992 bytes (285 MB) / 1043791872 bytes (995 MB) up to 3817799680 bytes (3640 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx4G
	AABB Pool Size: 385 (21560 bytes; 0 MB) allocated, 339 (18984 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 39 (2184 bytes; 0 MB) allocated, 37 (2072 bytes; 0 MB) used
	Player Count: 1 / 8; [mp['Spyro12321'/29, l='Autumn Planarium', x=480.94, y=4.00, z=2062.92]]
	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-772236/35811116/