So I was trying to open the server file on my mac with 8GB RAM. This is the file I was using 

#!/bin/bash
export JAVA_HOME=$(/usr/libexec/java_home -v 13.0.2)
cd "$(dirname "$0")"
exec Java -Xms8G -Xmx8G -jar server.jar

 

when I open this I get this error

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:567)

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

logout

Saving session...

...copying shared history...

...saving history...truncating history files...

...completed.

 

[Process completed]

 

 

The server opens fine with just the java file.

1.12 is no longer supported on these forums due to age.

Please update to a modern version to receive support here.

 

More information on supported versions can be found in the LTS link at the top of every page.

So the mods I am using are 1.12.2 so am I just SOL?