MenuBarSkin's constructor gets NPE from this:

import com.sun.javafx.scene.control.skin.MenuBarSkin;
import javafx.application.Application;
import javafx.scene.control.MenuBar;
import javafx.stage.Stage;

public class HelloMenu extends Application {

    @Override public void start(Stage stage) {
        MenuBar menuBar = new MenuBar();
        MenuBarSkin menuBarSkin = new MenuBarSkin(menuBar);
    }
    public static void main(String[] args) {
        Application.launch(args);
    }
}