java.lang.NullPointerException
	at org.netbeans.spi.java.project.support.ui.PackageViewChildren$PackageNode.getName(PackageViewChildren.java:469)
	at org.openide.nodes.FilterNode.getName(FilterNode.java:417)
[catch] at org.openide.explorer.view.VisualizerNode.run(VisualizerNode.java:343)
...