diff --git a/src/CodeNav.OutOfProc/Languages/CSharp/Mappers/ClassMapper.cs b/src/CodeNav.OutOfProc/Languages/CSharp/Mappers/ClassMapper.cs
index 07c56b9..9da7c84 100644
--- a/src/CodeNav.OutOfProc/Languages/CSharp/Mappers/ClassMapper.cs
+++ b/src/CodeNav.OutOfProc/Languages/CSharp/Mappers/ClassMapper.cs
@@ -70,7 +70,7 @@ public static CodeClassItem MapClass(ClassDeclarationSyntax member,
                 {
                     // If it is part of a region, add the implemented interface item to the region, add the member to the interface item
                     var regionItem = RegionMapper.GetRegion(regions, implementedInterfaceItemMember);
-                    AddImplementedInterfaceMember(regionItem, implementedInterfaceItem, implementedInterfaceItemMember);
+                    AddImplementedInterfaceMember(regionItem!, implementedInterfaceItem, implementedInterfaceItemMember);
                 }
                 else
                 {
diff --git a/src/CodeNav.OutOfProc/Services/CodeDocumentService.cs b/src/CodeNav.OutOfProc/Services/CodeDocumentService.cs
index 67cfcb9..1a633be 100644
--- a/src/CodeNav.OutOfProc/Services/CodeDocumentService.cs
+++ b/src/CodeNav.OutOfProc/Services/CodeDocumentService.cs
@@ -5,6 +5,7 @@
 using CodeNav.OutOfProc.Models;
 using CodeNav.OutOfProc.ViewModels;
 using Microsoft.VisualStudio.Extensibility;
+using Microsoft.VisualStudio.Extensibility.ToolWindows;
 using Microsoft.VisualStudio.Extensibility.UI;
 using System.Windows;
 
@@ -36,6 +37,8 @@ public class CodeDocumentService(
 
     public OutliningService OutliningService => outliningService;
 
+    public ToolWindow? ToolWindow { get; set; }
+
     public async Task<CodeDocumentViewModel> UpdateCodeDocumentViewModel(
         VisualStudioExtensibility? extensibility,
         string? filePath,
@@ -80,9 +83,16 @@ public async Task<CodeDocumentViewModel> UpdateCodeDocumentViewModel(
             if (!codeItems.Any())
             {
                 CodeDocumentViewModel.CodeItems = PlaceholderHelper.CreateNoCodeItemsFound();
+
+                // No code items found, hide the tool window after showing the "No code items found" message
+                await HideToolWindow(cancellationToken);
+                
                 return CodeDocumentViewModel;
             }
 
+            // Code items were found, make sure the tool window is visible
+            await ShowToolWindow(cancellationToken);
+
             // Sort the list of code items,
             // And update the DataContext for the tool window
             CodeDocumentViewModel.CodeItems = SortHelper.Sort(codeItems, CodeDocumentViewModel.SortOrder);
@@ -204,4 +214,24 @@ public async Task LoadGlobalSettings(bool readFromDisk = false)
             await LogHelper.LogException(this, "Error loading global settings", e);
         }
     }
+
+    private async Task HideToolWindow(CancellationToken cancellationToken)
+    {
+        if (ToolWindow == null)
+        {
+            return;
+        }
+
+        await ToolWindow.HideAsync(cancellationToken);
+    }
+
+    private async Task ShowToolWindow(CancellationToken cancellationToken)
+    {
+        if (ToolWindow == null)
+        {
+            return;
+        }
+
+        await ToolWindow.ShowAsync(activate: false, cancellationToken);
+    }
 }
diff --git a/src/CodeNav.OutOfProc/ToolWindows/CodeNavToolWindow.cs b/src/CodeNav.OutOfProc/ToolWindows/CodeNavToolWindow.cs
index 2a386da..7d7af86 100644
--- a/src/CodeNav.OutOfProc/ToolWindows/CodeNavToolWindow.cs
+++ b/src/CodeNav.OutOfProc/ToolWindows/CodeNavToolWindow.cs
@@ -6,7 +6,7 @@
 namespace CodeNav.OutOfProc.ToolWindows;
 
 [VisualStudioContribution]
-internal class CodeNavToolWindow(CodeDocumentService documentService) : ToolWindow
+internal class CodeNavToolWindow(CodeDocumentService codeDocumentService) : ToolWindow
 {
     public override ToolWindowConfiguration ToolWindowConfiguration => new()
     {
@@ -20,9 +20,11 @@ public override Task InitializeAsync(CancellationToken cancellationToken)
     {
         Title = "CodeNav";
 
+        codeDocumentService.ToolWindow = this;
+
         return Task.CompletedTask;
     }
 
     public override Task<IRemoteUserControl> GetContentAsync(CancellationToken cancellationToken)
-        => Task.FromResult<IRemoteUserControl>(new CodeNavToolWindowControl(documentService.CodeDocumentViewModel));
+        => Task.FromResult<IRemoteUserControl>(new CodeNavToolWindowControl(codeDocumentService.CodeDocumentViewModel));
 }
diff --git a/src/CodeNav/Services/TextViewService.cs b/src/CodeNav/Services/TextViewService.cs
index e7dca15..46e0e86 100644
--- a/src/CodeNav/Services/TextViewService.cs
+++ b/src/CodeNav/Services/TextViewService.cs
@@ -140,8 +140,13 @@ private async Task<IVsTextView> GetCurrentNativeTextViewAsync()
     /// Gets the text view from the window frame.
     /// </summary>
     /// <returns><see langword="null"/> if the window isn't a document window.</returns>
-    private async Task<IWpfTextView?> GetTextView(IVsWindowFrame windowFrame)
+    private async Task<IWpfTextView?> GetTextView(IVsWindowFrame? windowFrame)
     {
+        if (windowFrame == null)
+        {
+            return null;
+        }
+
         try
         {
             await ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync();