Server crash when old world load (1.0.9)

[Oakrin]

Whenever I start up my Server it crashes when the world loads.

Crash Report;

---- Minecraft Crash Report ----

// Hi. I'm Minecraft, and I'm a crashaholic.

 

Time: 3/4/14 12:33 PM

Description: Exception in server tick loop

 

cpw.mods.fml.common.DuplicateModsFoundException

at cpw.mods.fml.common.Loader.identifyDuplicates(Loader.java:396)

at cpw.mods.fml.common.Loader.identifyMods(Loader.java:354)

at cpw.mods.fml.common.Loader.loadMods(Loader.java:484)

at cpw.mods.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:99)

at cpw.mods.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:350)

at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:69)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:445)

at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:583)