Window Builder not letting me add buttons to Application Window

Question

When I click to ad a button to the window it does not do anything for some reason, a few days ago it was working fine and then I found out I had been using an old version of Window Builder and updated it, now for some reason it does not work and I cannot add anything to the window Screenshot of the issue

I tried adding JLabel first and when that didn't work I tried it with a button too and that also did not work, the button is highlighted but does not appear when i try to add it to the window

I have attached my Java Code below:

import java.awt.EventQueue; 

import javax.swing.JFrame;
import java.awt.Color;

public class GameMain {

    private JFrame frmComputerScienceIa;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    GameMain window = new GameMain();
                    window.frmComputerScienceIa.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public GameMain() {
        initialize();
    }

    /**
     * Initialise the contents of the frame.
     */
    private void initialize() {
        frmComputerScienceIa = new JFrame();
        frmComputerScienceIa.getContentPane().setBackground(new Color(0, 0, 0));
        frmComputerScienceIa.setBackground(new Color(0, 0, 0));
        frmComputerScienceIa.setTitle("COMPUTER SCIENCE IA");
        frmComputerScienceIa.setBounds(100, 100, 1299, 640);
        frmComputerScienceIa.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frmComputerScienceIa.getContentPane().setLayout(null);
    }

}