InitPopupMenu throwing error in AbstractResourceNavTreeNode

As part of my Designer module development I want to be able to store device configuration information in the Project Browser.

I have a class that extends AbstractResourceNavTreeNode that will represent the configuration objects in the browser. I have not written any initPopupMenu code - just using the base functionality from AbstractResourceNavTreenode.

When I right-click on one of these objects to bring up the basic edit functions (Rename, Cut, Copy, Paste, Delete), an Error dialog pops up that has no error message in it, and the console is showing ERROR [AbstractRsourceNavTreeNode-AWT-EventQueue-0].

If I add an initPopupMenu method and call setupEditActions() and addEditActions() directly, I can see that the error is being thrown during the addEditActions() call. No Exception is being returned to my call.

One of my other classes (that extends FolderNode) is set up as an EditActionHandler. and I can see that being tested during the setupEditActions() call when I run in debug, so the EditActionHandler is being found.

Any suggestions? Should I be extending ResourceNode instead of AbstractResourceNavTreeNode?