Index: Core/Plugins/src/Core.Plugins.DotSpatial/Legend/MapLegendView.cs
===================================================================
diff -u -rd72c02e33c5e53b6048a701cd68673db7053726b -ra8bfa77f57c57a5195ebc5a01ffdeca7bae3cf6b
--- Core/Plugins/src/Core.Plugins.DotSpatial/Legend/MapLegendView.cs	(.../MapLegendView.cs)	(revision d72c02e33c5e53b6048a701cd68673db7053726b)
+++ Core/Plugins/src/Core.Plugins.DotSpatial/Legend/MapLegendView.cs	(.../MapLegendView.cs)	(revision a8bfa77f57c57a5195ebc5a01ffdeca7bae3cf6b)
@@ -92,6 +92,11 @@
             }
             set
             {
+                if (IsDisposed)
+                {
+                    return;
+                }
+
                 treeViewControl.Data = (MapData) value;
             }
         }
Index: Core/Plugins/src/Core.Plugins.DotSpatial/MapRibbon.xaml.cs
===================================================================
diff -u -r6522a9f7396e770f8ecdcfda59c0966a86f6fb23 -ra8bfa77f57c57a5195ebc5a01ffdeca7bae3cf6b
--- Core/Plugins/src/Core.Plugins.DotSpatial/MapRibbon.xaml.cs	(.../MapRibbon.xaml.cs)	(revision 6522a9f7396e770f8ecdcfda59c0966a86f6fb23)
+++ Core/Plugins/src/Core.Plugins.DotSpatial/MapRibbon.xaml.cs	(.../MapRibbon.xaml.cs)	(revision a8bfa77f57c57a5195ebc5a01ffdeca7bae3cf6b)
@@ -79,7 +79,10 @@
             return RibbonControl;
         }
 
-        public void ValidateItems() {}
+        public void ValidateItems()
+        {
+            ToggleLegendViewButton.IsChecked = ToggleLegendViewCommand != null && ToggleLegendViewCommand.Checked;
+        }
 
         public bool IsContextualTabVisible(string tabGroupName, string tabName)
         {