I am unable to run my server with forge and mods on it

Hi i am getting this error for some apparent reason:

We appear to be missing one or more essential library files.

You will need to add them to your server before FML and Forge will run successfu

lly.java.lang.ClassNotFoundException: net.minecraft.launchwrapper.Launch

        at java.net.URLClassLoader$1.run(Unknown Source)

        at java.net.URLClassLoader$1.run(Unknown Source)

        at java.security.AccessController.doPrivileged(Native Method)

        at java.net.URLClassLoader.findClass(Unknown Source)

        at java.lang.ClassLoader.loadClass(Unknown Source)

        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)

        at java.lang.ClassLoader.loadClass(Unknown Source)

        at java.lang.Class.forName0(Native Method)

        at java.lang.Class.forName(Unknown Source)

        at cpw.mods.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.j

ava:25)

        at cpw.mods.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.

java:12)