ModernDocking.exception.DockableRegistrationFailureException on shutdown

[tlf30]

I'm probably forgetting something (especially considering I've been using your library for a couple years now and should know how to do this) but I am getting an exception when I shutdown my app. Something to note, this is a new app that is a re-write of my old one, so the docking system has been re-implemented from the ground up.

Exception in thread "AWT-EventQueue-0" ModernDocking.exception.DockableRegistrationFailureException: No root panel for window has been registered.
	at ModernDocking.internal.DockingComponentUtils.rootForWindow(DockingComponentUtils.java:92)
	at ModernDocking.api.DockingStateAPI.getWindowLayout(DockingStateAPI.java:69)
	at ModernDocking.api.DockingStateAPI.getApplicationLayout(DockingStateAPI.java:92)
	at ModernDocking.api.AppStateAPI$1.actionPerformed(AppStateAPI.java:132)
	at java.desktop/javax.swing.Timer.fireActionPerformed(Timer.java:311)
	at java.desktop/javax.swing.Timer$DoPostEvent.run(Timer.java:243)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

It looks like the exception is related to trying to persist the state of the app while it is shutting down and the root window no longer exists. This DOES NOT seem to affect the functionality of the persistence system.

I'm running the latest version as of this issue:

//Swing
    modernDockingVersion = '0.11.5'
    flatlafVersion = '3.4.1'
    miglayoutVersion = '11.3'
    beanbindingsVersion = '1.2.1'
    swingxVersion = '1.6.1'
    jlineVersion = '2.14.6'

As always, thank you so much for the awesome work and fantastic library.

EDIT:
As a note, my shutdown for the main UI looks like this:

 public void shutdown() {
        AppState.persist();
        try {
            Docking.deregisterAllDockables();
        } catch (DockableRegistrationFailureException drfe) {
            //Ignore
        }
        Docking.deregisterAllDockingPanels();
        
        //Other logic censored.....

        this.dispose();
    }

Which is similar of my old app.

[andrewauclair]

Looks like an issue I was seeing while fixing #223. That is likely the source.

[andrewauclair]

Release 0.11.6 has been published to Maven Central with a fix for this issue.