Custom Server: Minecraft 1.7.10, Mods, and Plugins

I created a custom server using: Minecraft Server 1.7.10, the latest forge for 1.7.10, and Kcauldron also the latest version for 1.7.10. It runs fine when I set the minecraft server 1.7.10 to the name custom_server.jar. When I set the other files as custom_server.jar it gives me this in the console log.

Code:

18.04 07:04:11 [Server] INFO /run.sh: line 31: 14945 Killed                  /monitor.sh "$PID" "$USER"
18.04 07:04:10 [Server] INFO at cpw.mods.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:12)
18.04 07:04:10 [Server] INFO at cpw.mods.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:25)
18.04 07:04:10 [Server] INFO at java.lang.Class.forName(Class.java:348)
18.04 07:04:10 [Server] INFO at java.lang.Class.forName0(Native Method)
18.04 07:04:10 [Server] INFO at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
18.04 07:04:10 [Server] INFO at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
18.04 07:04:10 [Server] INFO at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
18.04 07:04:10 [Server] INFO at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
18.04 07:04:10 [Server] INFO You will need to add them to your server before FML and Forge will run successfully.java.lang.ClassNotFoundException: net.minecraft.launchwrapper.Launch
18.04 07:04:10 [Server] INFO We appear to be missing one or more essential library files.
18.04 07:04:09 [Server] INFO /usr/bin/java $START
18.04 07:04:08 [Multicraft] Loaded config for "Mod: Custom Server"
18.04 07:04:08 [Multicraft] Starting server!
18.04 07:04:08 [Multicraft] Loading server properties
18.04 07:04:08 [Multicraft] Received start command

Please help.

 

UPDATE: I got spigot to work as custom_server.jar, but the forge didn't load. I then set forge as the custom_server.jar and spigot didn't load.