I've used forge for years with minecraft and I know my way around java and setting up a dedicated server, however I'm stumped this time.

I have the latest version, as mentioned in the title currently, installed on my dedicated server which the game server will run off of, and I am able to start the minecraft jar file to start up vanilla minecraft and run it perfectly fine, however when I try to start the forge file, nothing happens. Oddly, I can take the exact same file and put it on my gaming computer, and forge starts minecraft perfectly fine.

 

The server runs Win 8.1 Pro, java is up to date, windows is up to date, there are no anti-virus or firewall softwares or any thing else running. It's a bare-bones system strictly for game servers for local game play. It's always ran perfectly fine in the past, nothing has changed other than the forge version I'm using. I was able to get a copy of the error log during startup though.

 

Quote

A problem occurred running the Server launcher.java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:62)
	at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:31)
Caused
 by: java.lang.ClassCastException: 
java.base/jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast
 to java.base/java.net.URLClassLoader
	at net.minecraft.launchwrapper.Launch.<init>(Launch.java:34)
	at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
	... 6 more

 

Oh alright. I could of sworn I have Java 8 installed but I just checked and it is Java 9. I never would have guessed that.

 

I installed Java 8 and it's working now. Thanks for the help