Hello,

 

so me and my friends are trying to set up a server. The version is 1.12.2 with the forge version 1.12.2-14.23.5.2768. The server is on a remote location, which I am accessing through Putty and WinSCP. Whenever I try to run the server with the command  java -Xmx1024M -Xms1024M -jar forge-1.12.2-14.23.5.2768-universal.jar nogui, it gives me the following message:

 

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(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:566)
        at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:70)
        at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:34)
Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader 'bootstrap')
        at net.minecraft.launchwrapper.Launch.<init>(Launch.java:34)
        at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
        ... 6 more

When trying to run this on my own desktop, it works just fine. The person running the server installed Java within the last week, so I assume it's up-to-date, and I re-installed the server (both of which were solutions offered. It ran vanilla just fine as well. Any advice on how I could fix this?

As in downgrade it? The version it showed when I did java -version is:

 

openjdk version "11.0.5" 2019-10-15
OpenJDK Runtime Environment (build 11.0.5+10-post-Debian-1deb10u1)
OpenJDK 64-Bit Server VM (build 11.0.5+10-post-Debian-1deb10u1, mixed mode, sharing)