I have just installed and re-installed forge-1.12.2-14.23.2.2611-universal into an empty folder using the installer and attempted to run it. Double-clicking gives me a brief second of appearance in task manager, and using a bat file gives me:
 
	 
 
	 
	C:\Users\Kira\Desktop\Starland>java -Xmx1G -Xms1G -jar forge-1.12.2-14.23.2.2611-universal.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(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 
	 
 
	There is no log, no trace of it. Help?