So I downloaded forge 1.12.2-14.23.5.2860 server pack and tried to run the .jar file. However, it is refusing to run and giving me an error telling me to check the console. No console is filed to my computer. Instead I tried to run it through terminal, but it gives me the following error. I have both Java 8 and JDK 17. Also in the previous servers I have run, usually I also get a run.sh and a run.bat file from the installer, but with 1.12.2, it doesn't seem to give me either. Does anyone know how to run the .jar file or get the run.sh file so I can get this server working?

kwmd@kwmds-iMac ~ % cd desktop

kwmd@kwmds-iMac desktop % cd testing

kwmd@kwmds-iMac testing % java -jar forge-1.12.2-14.23.5.2860.jar

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:77)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.base/java.lang.reflect.Method.invoke(Method.java:568)

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

Use Java 8 - remove newer versions

Ok so I removed a JDK 17 and it worked thank you very much. 
But do you know how to set the jvm arguments so I can increase the ram. When I ran the server the run.sh and the user_jvm_args.txt both didn't pop up. I tried to copy over the run.sh file from a previous server and the jvm args I had for it, but it gave an error saying "Error: Could not find or load main class @user_jvm_args.txt" when I clearly had the jvm args text in it. 

Edited August 24, 20241 yr by amogussus
Spelling

Remove  @user_jvm_args.txt from the script and replace it with -Xmx4G 

 

Thank you, I figured it out, just had to add a nogui line in the script with -Xmx8G