Empty window

Question

I press Business Catalyst, and see this window:
After a moment it's disappears and nothing happens. It is a bug?

Answer 1

I'm sorry, I did it in a hurry, because I've got an examination tomorrow. I didn't copy the code for removing the titlebar because it didn't work anyway. Another attempt...
import javax.swing.*;
import java.awt.*;
public class GUI {
     protected JFrame frame= new JFrame("Title");
     protected JPanel titlePanel, mainPanel;
     private static final GUI gui = new GUI();
     public GUI(){
          titlePanel=new JPanel();
          mainPanel=new JPanel();
          frame.getContentPane().add(titlePanel,BorderLayout.PAGE_START);
          frame.getContentPane().add(mainPanel,BorderLayout.CENTER);
          frame.pack();
     public void createAndShowGUI(){
                JFrame.setDefaultLookAndFeelDecorated(true);
                frame.getLayeredPane().getComponent(1).setVisible(false);
                frame.setLocationRelativeTo(null);
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          frame.setVisible(true);
          frame.setResizable(false);
          frame.setIconImage(new ImageIcon("C:\\...\\editorIcon.jpg").getImage());
     public static void main(String[] args){
          SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                gui.createAndShowGUI();
}PS: I don't know if they're relevant, so I post them...