Index: Core/Plugins/src/Core.Plugins.ProjectExplorer/ProjectExplorer.cs
===================================================================
diff -u -raadef283cdf782eaefc208b8a40df9c568fdaece -rbaad48637e3584cfda7d0b67bbb61800f8d3dfe2
--- Core/Plugins/src/Core.Plugins.ProjectExplorer/ProjectExplorer.cs	(.../ProjectExplorer.cs)	(revision aadef283cdf782eaefc208b8a40df9c568fdaece)
+++ Core/Plugins/src/Core.Plugins.ProjectExplorer/ProjectExplorer.cs	(.../ProjectExplorer.cs)	(revision baad48637e3584cfda7d0b67bbb61800f8d3dfe2)
@@ -87,7 +87,7 @@
             }
             set
             {
-                if (!treeViewControl.IsDisposed)
+                if (treeViewControl != null && !treeViewControl.IsDisposed)
                 {
                     treeViewControl.Data = value;
                 }