To fix this, go to http://files.minecraftforge.net/fmllibs/
Download the following to your "lib" folder:
bcprov-jdk15on-148.jar.stash
scala-library.jar.stash
[*]Remove the ".stash" extension so that the files now end in ".jar"
[*]Run launch.(bat/sh) again
Your server should now work fine...
Hope this helps, Aristaeus.