Problem Mindcrack V7 Server Crash Error (Need help ASAP)

[Whip]

Every time I start up my server I get a error which is stopping my server from starting up and working. If anyone could tell me how to fix this problem I would be very happy!

Sample of error:
---- Minecraft Crash Report ----
// I blame Dinnerbone.

Time: 1/10/13 10:56 PM
Description: Exception in server tick loop

cpw.mods.fml.common.DuplicateModsFoundException
at cpw.mods.fml.common.Loader.identifyDuplicates(Loader.java:374)
at cpw.mods.fml.common.Loader.identifyMods(Loader.java:335)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:457)
at cpw.mods.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:86)
at cpw.mods.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:345)
at ho.c(DedicatedServer.java:64)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:458)
at fy.run(SourceFile:849)


A detailed walkthrough of the error, its code path and all known details is as follows:
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-- System Details --
Details:
Minecraft Version: 1.4.6
Operating System: Linux (i386) version 2.6.18-308.8.2.el5.028stab101.1