diff --git a/src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/IndexPad.cs b/src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/IndexPad.cs
index 3ccbb84693..08685e8d81 100644
--- a/src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/IndexPad.cs
+++ b/src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/IndexPad.cs
@@ -169,12 +169,23 @@ namespace HtmlHelp2
 		{
 			if (!this.controlIsEnabled) return;
 			
-			searchTerm.Text                       = "";
-			searchTerm.Items.Clear();
-			indexControl.IndexData                = HtmlHelp2Environment.GetIndex(HtmlHelp2Environment.CurrentFilterQuery);
-			filterCombobox.SelectedIndexChanged  -= new EventHandler(FilterChanged);
-			HtmlHelp2Environment.BuildFilterList(filterCombobox);
-			filterCombobox.SelectedIndexChanged  += new EventHandler(FilterChanged);
+			try
+			{
+				searchTerm.Text                       = "";
+				searchTerm.Items.Clear();
+				indexControl.IndexData                = HtmlHelp2Environment.GetIndex(HtmlHelp2Environment.CurrentFilterQuery);
+				filterCombobox.SelectedIndexChanged  -= new EventHandler(FilterChanged);
+				HtmlHelp2Environment.BuildFilterList(filterCombobox);
+				filterCombobox.SelectedIndexChanged  += new EventHandler(FilterChanged);
+			}
+			catch
+			{
+				LoggingService.Error("Help 2.0: cannot connect to IHxIndex interface (Index)");
+				indexControl.Enabled = false;
+				indexControl.BackColor = SystemColors.ButtonFace;
+				filterCombobox.Enabled = false;
+				searchTerm.Enabled = false;
+			}
 		}
 
 		private void FilterChanged(object sender, EventArgs e)
diff --git a/src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/TocPad.cs b/src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/TocPad.cs
index 5b62782cc9..7f76dbd272 100644
--- a/src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/TocPad.cs
+++ b/src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/TocPad.cs
@@ -205,10 +205,20 @@ namespace HtmlHelp2
 		{
 			if (!this.controlIsEnabled) return;
 
-			tocControl.Hierarchy                 = HtmlHelp2Environment.GetTocHierarchy(HtmlHelp2Environment.CurrentFilterQuery);
-			filterCombobox.SelectedIndexChanged -= new EventHandler(this.FilterChanged);
-			HtmlHelp2Environment.BuildFilterList(filterCombobox);
-			filterCombobox.SelectedIndexChanged += new EventHandler(this.FilterChanged);
+			try
+			{
+				tocControl.Hierarchy                 = HtmlHelp2Environment.GetTocHierarchy(HtmlHelp2Environment.CurrentFilterQuery);
+				filterCombobox.SelectedIndexChanged -= new EventHandler(this.FilterChanged);
+				HtmlHelp2Environment.BuildFilterList(filterCombobox);
+				filterCombobox.SelectedIndexChanged += new EventHandler(this.FilterChanged);
+			}
+			catch
+			{
+				LoggingService.Error("Help 2.0: cannot connect to IHxHierarchy interface (Contents)");
+				tocControl.Enabled = false;
+				tocControl.BackColor = SystemColors.ButtonFace;
+				filterCombobox.Enabled = false;
+			}
 		}
 
 		private void FilterChanged(object sender, EventArgs e)
diff --git a/src/AddIns/Misc/HtmlHelp2/Project/src/Service/HtmlHelp2Service.cs b/src/AddIns/Misc/HtmlHelp2/Project/src/Service/HtmlHelp2Service.cs
index 4b7253176d..ee56490dcc 100644
--- a/src/AddIns/Misc/HtmlHelp2/Project/src/Service/HtmlHelp2Service.cs
+++ b/src/AddIns/Misc/HtmlHelp2/Project/src/Service/HtmlHelp2Service.cs
@@ -202,34 +202,16 @@ namespace HtmlHelp2.Environment
 
 		public static IHxHierarchy GetTocHierarchy(string filterQuery)
 		{
-			try
-			{
-				IHxHierarchy defaultToc =
-					(IHxHierarchy)session.GetNavigationInterface("!DefaultTOC", filterQuery, ref TocGuid);
-				return defaultToc;
-			}
-			catch
-			{
-				LoggingService.Error("Help 2.0: cannot connect to IHxHierarchy interface (Contents)");
-				return null;
-			}
+			IHxHierarchy defaultToc =
+				(IHxHierarchy)session.GetNavigationInterface("!DefaultTOC", filterQuery, ref TocGuid);
+			return defaultToc;
 		}
 
 		public static IHxIndex GetIndex(string filterQuery)
 		{
-			try
-			{
-				IHxIndex defaultIndex =
-					(IHxIndex)session.GetNavigationInterface("!DefaultKeywordIndex",
-					                                         filterQuery,
-					                                         ref IndexGuid);
-				return defaultIndex;
-			}
-			catch
-			{
-				LoggingService.Error("Help 2.0: cannot connect to IHxIndex interface (Index)");
-				return null;
-			}
+			IHxIndex defaultIndex =
+				(IHxIndex)session.GetNavigationInterface("!DefaultKeywordIndex", filterQuery, ref IndexGuid);
+			return defaultIndex;
 		}
 
 		public static void BuildFilterList(ComboBox filterCombobox)