diff -r 9b0eb87ded94 projectui/src/org/netbeans/modules/project/ui/ProjectsRootNode.java
--- a/projectui/src/org/netbeans/modules/project/ui/ProjectsRootNode.java	Sat Sep 03 06:38:29 2016 +0000
+++ b/projectui/src/org/netbeans/modules/project/ui/ProjectsRootNode.java	Mon Sep 05 14:45:44 2016 +0300
@@ -341,9 +341,9 @@
                         
             if (type == PHYSICAL_VIEW) {
                 final Sources sources = p.data.second().first();
-                final SourceGroup[] groups = p.data.second().second();
                 sources.removeChangeListener( this );
                 sources.addChangeListener( this );
+                final SourceGroup[] groups = p.data.second().second();
                 sources2projects.put( sources, new WeakReference<Project>( project ) );
                 final List<Node> nodes = new ArrayList<>(groups.length);
                 for (SourceGroup group : groups) {