Hopper: java.lang.IllegalStateException: Already tesselating!

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-192044/

Crash:

java.lang.IllegalStateException: Already tesselating!
	at bfq.b(SourceFile:171)
	at bfl.a(SourceFile:735)
	at bfe.a(SourceFile:797)

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

---- Minecraft Crash Report ----
// I just don't know what went wrong :(

Time: 9/22/13 11:50 AM
Description: Unexpected error

java.lang.IllegalStateException: Already tesselating!
	at bfq.b(SourceFile:171)
	at bfl.a(SourceFile:735)
	at bfe.a(SourceFile:797)
	at bfe.b(SourceFile:693)
	at atv.S(SourceFile:686)
	at atv.d(SourceFile:619)
	at net.minecraft.client.main.Main.main(SourceFile:101)


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

-- Head --
Stacktrace:
	at bfq.b(SourceFile:171)
	at bfl.a(SourceFile:735)
	at bfe.a(SourceFile:797)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bdi['sam0murphy'/475231, l='MpServer', x=-539.45, y=89.98, z=13.32]]
	Chunk stats: MultiplayerChunkCache: 441
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-540,4,-4), Chunk: (at 4,0,12 in -34,-1; contains blocks -544,0,-16 to -529,255,-1), Region: (-2,-1; contains chunks -64,-32 to -33,-1, blocks -1024,0,-512 to -513,255,-1)
	Level time: 380 game time, 380 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 1 total; [bdi['sam0murphy'/475231, l='MpServer', x=-539.45, y=89.98, z=13.32]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Non-integrated multiplayer server
Stacktrace:
	at bdd.a(SourceFile:284)
	at atv.b(SourceFile:1761)
	at atv.d(SourceFile:633)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.4
	Operating System: Mac OS X (x86_64) version 10.6.8
	Java Version: 1.6.0_51, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 9995272 bytes (9 MB) / 530186240 bytes (505 MB) up to 530186240 bytes (505 MB)
	JVM Flags: 1 total; -Xmx512M
	AABB Pool Size: 2 (112 bytes; 0 MB) allocated, 2 (112 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 1.6.4
	LWJGL: 2.9.0
	OpenGL: NVIDIA GeForce 8800 GT OpenGL Engine GL version 2.1 NVIDIA-1.6.36, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Default
	Current Language: English (US)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 22 (1232 bytes; 0 MB) allocated, 22 (1232 bytes; 0 MB) used

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-192044/13445959/