Red word in ftb console

2013-03-10 10:48:05 [INFO] [STDERR] Exception in thread "Server thread" java.lang.IllegalArgumentException: Failed to register dimension for id 7, One is already registered
2013-03-10 10:48:05 [INFO] [STDERR] at net.minecraftforge.common.DimensionManager.registerDimension(DimensionManager.java:125)
2013-03-10 10:48:05 [INFO] [STDERR] at com.xcompwiz.mystcraft.Mystcraft.registerDimensions(Mystcraft.java:400)
2013-03-10 10:48:05 [INFO] [STDERR] at com.xcompwiz.mystcraft.Mystcraft.serverStart(Mystcraft.java:359)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at java.lang.reflect.Method.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:487)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at java.lang.reflect.Method.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:69)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.EventBus.dispatch(EventBus.java:317)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:300)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.EventBus.post(EventBus.java:268)
2013-03-10 10:48:05 [INFO] [STDERR] at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:153)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at java.lang.reflect.Method.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:69)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.EventBus.dispatch(EventBus.java:317)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:300)
2013-03-10 10:48:05 [INFO] [STDERR] at com.google.common.eventbus.EventBus.post(EventBus.java:268)
2013-03-10 10:48:05 [INFO] [STDERR] at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:86)
2013-03-10 10:48:05 [INFO] [STDERR] at cpw.mods.fml.common.Loader.serverStarting(Loader.java:721)
2013-03-10 10:48:05 [INFO] [STDERR] at cpw.mods.fml.common.FMLCommonHandler.handleServerStarting(FMLCommonHandler.java:315)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at java.lang.reflect.Method.invoke(Unknown Source)
2013-03-10 10:48:05 [INFO] [STDERR] at Reflector.callBoolean(Reflector.java:301)
2013-03-10 10:48:05 [INFO] [STDERR] at bdz.c(IntegratedServer.java:145)
2013-03-10 10:48:05 [INFO] [STDERR] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:458)
2013-03-10 10:48:05 [INFO] [STDERR] at fy.run(SourceFile:849)