My Minecraft server crashes when I join

Description: Exception ticking world

java.lang.RuntimeException: Already decorating
	at alg.a(SourceFile:23)
	at akz.a(SourceFile:387)
	at alv.a(SourceFile:74)
	at avt.a(SourceFile:443)
	at ny.a(SourceFile:175)
	at aup.a(SourceFile:855)
	at ny.c(SourceFile:104)
	at ny.d(SourceFile:117)
	at akh.b(SourceFile:287)
	at nz.h(SourceFile:271)
	at nz.c(SourceFile:162)
	at net.minecraft.server.MinecraftServer.w(SourceFile:539)
	at mz.w(SourceFile:272)
	at net.minecraft.server.MinecraftServer.v(SourceFile:481)
	at net.minecraft.server.MinecraftServer.run(SourceFile:397)
	at mq.run(SourceFile:667)

Open the command line and type

java -version

Then hit enter and post the result here.

java version "1.1.0_51"
java(TM) SE Runtime Enviroment (build 1.7.0_51-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)

-Hope This is what you needed

This ticket has been marked as a duplicate of MC-58795, in favor of the more general or better information provided.