ADDITIONAL SYSTEM INFORMATION :
macOS 10.15 Catalina, Beta

A DESCRIPTION OF THE PROBLEM :
When trying to show a FileDialog in macOS 10.15 Beta the dialog doesn't open and I get the following error message:

2019-07-12 15:26:40.451 java[17097:242412] +[NSXPCSharedListener endpointForReply:withListenerName:]: an error occurred while attempting to obtain endpoint for listener 'com.apple.view-bridge': Connection interrupted

Looks like in macOS Beta all panels behave as if they were sandboxed. Here are some resources I've found about people having this same issue:

https://github.com/xamarin/xamarin-macios/issues/6474
https://www.emaculation.com/forum/viewtopic.php?f=20&t=10249&sid=2b8ec1b2576eece87a89f8dbc2355d89

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Build the simple FileDialog example provided, press the button to open the dialog.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
File Dialog should open.
ACTUAL -
The console prints:
2019-07-12 15:26:40.451 java[17097:242412] +[NSXPCSharedListener endpointForReply:withListenerName:]: an error occurred while attempting to obtain endpoint for listener 'com.apple.view-bridge': Connection interrupted

---------- BEGIN SOURCE ----------
// Source code taken from https://www.tutorialspoint.com/awt/awt_filedialog

package com.tutorialspoint.gui;

import java.awt.*;
import java.awt.event.*;

public class AwtControlDemo {

   private Frame mainFrame;
   private Label headerLabel;
   private Label statusLabel;
   private Panel controlPanel;

   public AwtControlDemo(){
      prepareGUI();
   }

   public static void main(String[] args){
      AwtControlDemo  awtControlDemo = new AwtControlDemo();
      awtControlDemo.showFileDialogDemo();
   }

   private void prepareGUI(){
      mainFrame = new Frame("Java AWT Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      headerLabel = new Label();
      headerLabel.setAlignment(Label.CENTER);
      statusLabel = new Label();        
      statusLabel.setAlignment(Label.CENTER);
      statusLabel.setSize(350,100);

      controlPanel = new Panel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }

   private void showFileDialogDemo(){
      headerLabel.setText("Control in action: FileDialog"); 

      final FileDialog fileDialog = new FileDialog(mainFrame,"Select file");
      Button showFileDialogButton = new Button("Open File");
      showFileDialogButton.addActionListener(new ActionListener() {
         @Override
         public void actionPerformed(ActionEvent e) {
            fileDialog.setVisible(true);
            statusLabel.setText("File Selected :" 
            + fileDialog.getDirectory() + fileDialog.getFile());
         }
      });

      controlPanel.add(showFileDialogButton);
      mainFrame.setVisible(true);  
   }
}
---------- END SOURCE ----------