FULL PRODUCT VERSION :
java version " 1.7.0_25 "
Java(TM) SE Runtime Environment (build 1.7.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 23.25-b01, mixed mode)

java version " 1.7.0_40-ea "
Java(TM) SE Runtime Environment (build 1.7.0_40-ea-b38)
Java HotSpot(TM) 64-Bit Server VM (build 24.0-b55, mixed mode)



ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
When JavaFX app contain Swing jDialog and jDialog is created first, then application is not starting from Web Start.

The same app will start as jar.


ERROR MESSAGES/STACK TRACES THAT OCCUR :

java.lang.NullPointerException
at sun.awt.windows.WWindowPeer.initActiveWindowsTracking(Unknown Source)
at sun.awt.windows.WWindowPeer.initialize(Unknown Source)
at sun.awt.windows.WFramePeer.initialize(Unknown Source)
at sun.awt.windows.WComponentPeer.<init>(Unknown Source)
at sun.awt.windows.WCanvasPeer.<init>(Unknown Source)
at sun.awt.windows.WPanelPeer.<init>(Unknown Source)
at sun.awt.windows.WWindowPeer.<init>(Unknown Source)
at sun.awt.windows.WFramePeer.<init>(Unknown Source)
at sun.awt.windows.WToolkit.createFrame(Unknown Source)
at java.awt.Frame.addNotify(Unknown Source)
at javax.swing.SwingUtilities$SharedOwnerFrame.addNotify(Unknown Source)
at java.awt.Dialog.addNotify(Unknown Source)
at java.awt.Dialog.conditionalShow(Unknown Source)
at java.awt.Dialog.show(Unknown Source)
at java.awt.Component.show(Unknown Source)
at java.awt.Component.setVisible(Unknown Source)
at java.awt.Window.setVisible(Unknown Source)
at java.awt.Dialog.setVisible(Unknown Source)
at error.Error.start(Error.java:23)
at com.sun.javafx.applet.FXApplet2$1.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$4$1.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$4$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$4.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(Unknown Source)
at com.sun.glass.ui.win.WinApplication$3$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Exception in runnable
java.lang.RuntimeException: java.lang.NullPointerException
at com.sun.javafx.applet.FXApplet2$1.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$4$1.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$4$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$4.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(Unknown Source)
at com.sun.glass.ui.win.WinApplication$3$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
at sun.awt.windows.WWindowPeer.initActiveWindowsTracking(Unknown Source)
at sun.awt.windows.WWindowPeer.initialize(Unknown Source)
at sun.awt.windows.WFramePeer.initialize(Unknown Source)
at sun.awt.windows.WComponentPeer.<init>(Unknown Source)
at sun.awt.windows.WCanvasPeer.<init>(Unknown Source)
at sun.awt.windows.WPanelPeer.<init>(Unknown Source)
at sun.awt.windows.WWindowPeer.<init>(Unknown Source)
at sun.awt.windows.WFramePeer.<init>(Unknown Source)
at sun.awt.windows.WToolkit.createFrame(Unknown Source)
at java.awt.Frame.addNotify(Unknown Source)
at javax.swing.SwingUtilities$SharedOwnerFrame.addNotify(Unknown Source)
at java.awt.Dialog.addNotify(Unknown Source)
at java.awt.Dialog.conditionalShow(Unknown Source)
at java.awt.Dialog.show(Unknown Source)
at java.awt.Component.show(Unknown Source)
at java.awt.Component.setVisible(Unknown Source)
at java.awt.Window.setVisible(Unknown Source)
at java.awt.Dialog.setVisible(Unknown Source)
at error.Error.start(Error.java:23)
... 10 more


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class Error extends Application {

    public JDialog jDialog = new JDialog();

    @Override
    public void start(Stage primaryStage) {
        StackPane root = new StackPane();

        Scene scene = new Scene(root, 800, 650);
        //jDialog = new JDialog();
        jDialog.setVisible(true);
        jDialog.setSize(800, 650);
        
        primaryStage.setTitle( " Hello World! " );
        primaryStage.setScene(scene);
        primaryStage.show();
    
    }

    public static void main(String[] args) {
        launch(args);
    }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
if jDialog is created in " start " method, then works fine