Server crash after internal exeption

---- Minecraft Crash Report ----
// Uh... Did I do that?

Time: 7/4/13 1:44 PM
Description: Ticking screen

java.lang.IllegalArgumentException: An objective with the name 'green' already exists!
	at atc.f(SourceFile:159)
	at bcn.a(SourceFile:1153)
	at ft.a(SourceFile:99)
	at cn.b(SourceFile:350)
	at bcn.d(SourceFile:95)
	at bcp.c(SourceFile:71)
	at atn.k(SourceFile:1172)
	at atn.S(SourceFile:662)
	at atn.d(SourceFile:618)
	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 atc.f(SourceFile:159)
	at bcn.a(SourceFile:1153)
	at ft.a(SourceFile:99)
	at cn.b(SourceFile:350)
	at bcn.d(SourceFile:95)
	at bcp.c(SourceFile:71)

-- Affected screen --
Details:
	Screen name: bcz

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bcx['RODynamo'/50221729, l='MpServer', x=8.50, y=66.62, z=8.50]]
	Chunk stats: MultiplayerChunkCache: 0
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-152,73,224), Chunk: (at 8,4,0 in -10,14; contains blocks -160,0,224 to -145,255,239), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 167333005 game time, 525196554 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: survival (ID 0). Hardcore: false. Cheats: false
	Forced entities: 1 total; [bcx['RODynamo'/50221729, l='MpServer', x=8.50, y=66.62, z=8.50]]
	Retry entities: 0 total; []
Stacktrace:
	at bcu.a(SourceFile:284)
	at atn.b(SourceFile:1743)
	at atn.d(SourceFile:627)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.1
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 92613040 bytes (88 MB) / 153481216 bytes (146 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 4625 (259000 bytes; 0 MB) allocated, 4625 (259000 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
	Launched Version: 1.6.1
	LWJGL: 2.9.0
	OpenGL: GeForce 9600 GT/PCIe/SSE2 GL version 3