My server keeps getting errors on start

[jmeyer73]

I'm trying to make a sky factory server and it keep giving me this error when I run ServerStart:
Starting server
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=256M; support was removed in 8.0
Java HotSpot(TM) 64-Bit Server VM warning: Using the ParNew young collector with the Serial old collector is deprecated and will likely be removed in a future release
A problem occurred running the Server launcher.java.lang.reflect.InvocationTargetException
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:43)
at cpw.mods.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:12)
Caused by: java.lang.NoClassDefFoundError: org/apache/logging/log4j/Level
at net.minecraft.launchwrapper.Launch.launch(Launch.java:94)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
... 6 more
Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.Level
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)
... 8 more
Exiting...

What does this mean? i've done everything i need to do i think so i don't know why it's doing this. Thanks in advance.

 

[Francis Baster]

Looks like you are missing files from the 'libraries' folder. Try reinstalling your server with the files from the server zip that you downloaded.