java.util.ConcurrentModificationException
        at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
        at java.util.ArrayList$Itr.remove(Unknown Source)
        at net.minecraft.launchwrapper.Launch.launch(Launch.java:114)
        at net.minecraft.launchwrapper.Launch.main(Launch.java:27)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at cpw.mods.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.j
ava:48)
        at cpw.mods.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.
java:17)