Rhinosaurus

The Bteam Jar file does not run correctly and I get this error at the end of the file that pops up after i try to run Bteam Jar file 2015-05-15 18:04:05 [SEVERE] [ForgeModLoader] Unable to launch 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.java:48) at cpw.mods.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:17)