DisplayLink Forum - 5.1 Crashes when launching Java 8 Swing app with closed lid

I have a macBook Pro (15-inch, Late 2016) running on macOS Mojave 10.14.3 with DisplayLink Driver 5.1 for the Dell Dock D6000.

I use a single external monitor with 1920x1200 resolution via a DisplayPort Adapter.

When I connect the macBook to the dock and close the lid, then I cannot start any Java Swing based application using JDK8 or JDK11.

You can use the following code to reproduce the problem. The code is based on a Stackoverflow example.

Code:

package dell_d6000;



import java.awt.GraphicsConfiguration;

import java.awt.GraphicsDevice;

import java.awt.GraphicsEnvironment;

import java.awt.Label;

import javax.swing.JFrame;



public class Demo {

        private static void print(String name) {

                System.out.println(name);

        }

        private static void print(String name, Object value) {

                System.out.println(name + ": '" + value + "'");

        }

        public static void main(String[] args) {

                print("=== Start ===");

                final GraphicsEnvironment localGraphicsEnvironment = GraphicsEnvironment.getLocalGraphicsEnvironment();

                print("localGraphicsEnvironment", localGraphicsEnvironment);

                final GraphicsDevice defaultScreenDevice = localGraphicsEnvironment.getDefaultScreenDevice();

                print("defaultScreenDevice", defaultScreenDevice);

                final GraphicsConfiguration defaultConfiguration = defaultScreenDevice.getDefaultConfiguration();

                print("defaultConfiguration", defaultConfiguration);

                print("'new JFrame(\"Demo\");' will produce a NullPointerException when defaultConfiguration is null. This is a DisplayLink Driver 5.1 bug");

                final JFrame frame = new JFrame("Demo");

                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                frame.getContentPane().add(new Label("*** Hello World! ***"));

                frame.pack();

                frame.setVisible(true);

                print("==== End ====");

        }

}

I get the following output with closed lid (or open lid with mirroring enabled):

Code:

=== Start ===

localGraphicsEnvironment: 'sun.awt.CGraphicsEnvironment@3d075dc0'

defaultScreenDevice: 'sun.awt.CGraphicsDevice@214c265e'

defaultConfiguration: 'null'

'new JFrame("Demo");' will produce a NullPointerException when defaultConfiguration is null. This is a DisplayLink Driver 5.1 bug

Exception in thread "main" java.lang.NullPointerException

        at java.awt.Window.init(Window.java:497)

        at java.awt.Window.<init>(Window.java:537)

        at java.awt.Frame.<init>(Frame.java:420)

        at javax.swing.JFrame.<init>(JFrame.java:233)

        at dell_d6000.Demo.main(Demo.java:29)

And I get the following, expected output with open lid and mirroring disabled (JFrame is shown on the macBook screen):

Code:

=== Start ===

localGraphicsEnvironment: 'sun.awt.CGraphicsEnvironment@6d03e736'

defaultScreenDevice: 'sun.awt.CGraphicsDevice@568db2f2'

defaultConfiguration: 'CGLGraphicsConfig[dev=69733447,pixfmt=0]'

'new JFrame("Demo");' will produce a NullPointerException when defaultConfiguration is null. This is a DisplayLink Driver 5.1 bug

==== End ====

This issue is related to:

- https://www.displaylink.org/forum/sh...ad.php?t=66114
- https://stackoverflow.com/questions/...rtup-on-mac-os

A fix for this issue would be very much appreciated.

Thank you.