diff --git a/src/Avalonia.Controls/ComboBox.cs b/src/Avalonia.Controls/ComboBox.cs
index 57c07916db..274696d501 100644
--- a/src/Avalonia.Controls/ComboBox.cs
+++ b/src/Avalonia.Controls/ComboBox.cs
@@ -1,6 +1,8 @@
 using System;
 using System.Linq;
+using System.Reactive.Disposables;
 using Avalonia.Controls.Generators;
+using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Shapes;
@@ -80,7 +82,7 @@ namespace Avalonia.Controls
         private bool _isDropDownOpen;
         private Popup _popup;
         private object _selectionBoxItem;
-        private IDisposable _subscriptionsOnOpen;
+        private readonly CompositeDisposable _subscriptionsOnOpen = new CompositeDisposable();
 
         /// <summary>
         /// Initializes static members of the <see cref="ComboBox"/> class.
@@ -291,6 +293,7 @@ namespace Avalonia.Controls
 
             _popup = e.NameScope.Get<Popup>("PART_Popup");
             _popup.Opened += PopupOpened;
+            _popup.Closed += PopupClosed;
         }
 
         internal void ItemFocused(ComboBoxItem dropDownItem)
@@ -303,8 +306,7 @@ namespace Avalonia.Controls
 
         private void PopupClosed(object sender, EventArgs e)
         {
-            _subscriptionsOnOpen?.Dispose();
-            _subscriptionsOnOpen = null;
+            _subscriptionsOnOpen.Clear();
 
             if (CanFocus(this))
             {
@@ -316,20 +318,34 @@ namespace Avalonia.Controls
         {
             TryFocusSelectedItem();
 
-            _subscriptionsOnOpen?.Dispose();
-            _subscriptionsOnOpen = null;
+            _subscriptionsOnOpen.Clear();
 
             var toplevel = this.GetVisualRoot() as TopLevel;
             if (toplevel != null)
             {
-                _subscriptionsOnOpen = toplevel.AddDisposableHandler(PointerWheelChangedEvent, (s, ev) =>
+                toplevel.AddDisposableHandler(PointerWheelChangedEvent, (s, ev) =>
                 {
                     //eat wheel scroll event outside dropdown popup while it's open
                     if (IsDropDownOpen && (ev.Source as IVisual).GetVisualRoot() == toplevel)
                     {
                         ev.Handled = true;
                     }
-                }, Interactivity.RoutingStrategies.Tunnel);
+                }, Interactivity.RoutingStrategies.Tunnel).DisposeWith(_subscriptionsOnOpen);
+            }
+
+            this.GetObservable(IsVisibleProperty).Subscribe(IsVisibleChanged).DisposeWith(_subscriptionsOnOpen);
+
+            foreach (var parent in this.GetVisualAncestors().OfType<IControl>())
+            {
+                parent.GetObservable(IsVisibleProperty).Subscribe(IsVisibleChanged).DisposeWith(_subscriptionsOnOpen);
+            }
+        }
+
+        private void IsVisibleChanged(bool isVisible)
+        {
+            if (!isVisible && IsDropDownOpen)
+            {
+                IsDropDownOpen = false;
             }
         }
 
diff --git a/src/Avalonia.Controls/Mixins/DisposableMixin.cs b/src/Avalonia.Controls/Mixins/DisposableMixin.cs
new file mode 100644
index 0000000000..9b30b4ba4c
--- /dev/null
+++ b/src/Avalonia.Controls/Mixins/DisposableMixin.cs
@@ -0,0 +1,38 @@
+using System;
+using System.Reactive.Disposables;
+
+namespace Avalonia.Controls.Mixins
+{
+    /// <summary>
+    /// Extension methods associated with the IDisposable interface.
+    /// </summary>
+    public static class DisposableMixin
+    {
+        /// <summary>
+        /// Ensures the provided disposable is disposed with the specified <see cref="CompositeDisposable"/>.
+        /// </summary>
+        /// <typeparam name="T">
+        /// The type of the disposable.
+        /// </typeparam>
+        /// <param name="item">
+        /// The disposable we are going to want to be disposed by the CompositeDisposable.
+        /// </param>
+        /// <param name="compositeDisposable">
+        /// The <see cref="CompositeDisposable"/> to which <paramref name="item"/> will be added.
+        /// </param>
+        /// <returns>
+        /// The disposable.
+        /// </returns>
+        public static T DisposeWith<T>(this T item, CompositeDisposable compositeDisposable)
+            where T : IDisposable
+        {
+            if (compositeDisposable is null)
+            {
+                throw new ArgumentNullException(nameof(compositeDisposable));
+            }
+
+            compositeDisposable.Add(item);
+            return item;
+        }
+    }
+}
diff --git a/src/Avalonia.Controls/Primitives/Popup.cs b/src/Avalonia.Controls/Primitives/Popup.cs
index d5fb69a672..e804c4b4a9 100644
--- a/src/Avalonia.Controls/Primitives/Popup.cs
+++ b/src/Avalonia.Controls/Primitives/Popup.cs
@@ -2,6 +2,7 @@ using System;
 using System.ComponentModel;
 using System.Linq;
 using System.Reactive.Disposables;
+using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Diagnostics;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives.PopupPositioning;
@@ -393,18 +394,8 @@ namespace Avalonia.Controls.Primitives
 
             var handlerCleanup = new CompositeDisposable(5);
 
-            void DeferCleanup(IDisposable? disposable)
-            {
-                if (disposable is null)
-                {
-                    return;
-                }
-
-                handlerCleanup.Add(disposable);
-            }
-
-            DeferCleanup(popupHost.BindConstraints(this, WidthProperty, MinWidthProperty, MaxWidthProperty,
-                HeightProperty, MinHeightProperty, MaxHeightProperty, TopmostProperty));
+            popupHost.BindConstraints(this, WidthProperty, MinWidthProperty, MaxWidthProperty,
+                HeightProperty, MinHeightProperty, MaxHeightProperty, TopmostProperty).DisposeWith(handlerCleanup);
 
             popupHost.SetChild(Child);
             ((ISetLogicalParent)popupHost).SetParent(this);
@@ -418,19 +409,19 @@ namespace Avalonia.Controls.Primitives
                 PlacementConstraintAdjustment,
                 PlacementRect);
 
-            DeferCleanup(SubscribeToEventHandler<IPopupHost, EventHandler<TemplateAppliedEventArgs>>(popupHost, RootTemplateApplied,
+            SubscribeToEventHandler<IPopupHost, EventHandler<TemplateAppliedEventArgs>>(popupHost, RootTemplateApplied,
                 (x, handler) => x.TemplateApplied += handler,
-                (x, handler) => x.TemplateApplied -= handler));
+                (x, handler) => x.TemplateApplied -= handler).DisposeWith(handlerCleanup);
 
             if (topLevel is Window window)
             {
-                DeferCleanup(SubscribeToEventHandler<Window, EventHandler>(window, WindowDeactivated,
+                SubscribeToEventHandler<Window, EventHandler>(window, WindowDeactivated,
                     (x, handler) => x.Deactivated += handler,
-                    (x, handler) => x.Deactivated -= handler));
+                    (x, handler) => x.Deactivated -= handler).DisposeWith(handlerCleanup);
                 
-                DeferCleanup(SubscribeToEventHandler<IWindowImpl, Action>(window.PlatformImpl, WindowLostFocus,
+                SubscribeToEventHandler<IWindowImpl, Action>(window.PlatformImpl, WindowLostFocus,
                         (x, handler) => x.LostFocus += handler,
-                        (x, handler) => x.LostFocus -= handler));
+                        (x, handler) => x.LostFocus -= handler).DisposeWith(handlerCleanup);
             }
             else
             {
@@ -438,13 +429,13 @@ namespace Avalonia.Controls.Primitives
 
                 if (parentPopupRoot?.Parent is Popup popup)
                 {
-                    DeferCleanup(SubscribeToEventHandler<Popup, EventHandler<EventArgs>>(popup, ParentClosed,
+                    SubscribeToEventHandler<Popup, EventHandler<EventArgs>>(popup, ParentClosed,
                         (x, handler) => x.Closed += handler,
-                        (x, handler) => x.Closed -= handler));
+                        (x, handler) => x.Closed -= handler).DisposeWith(handlerCleanup);
                 }
             }
 
-            DeferCleanup(InputManager.Instance?.Process.Subscribe(ListenForNonClientClick));
+            InputManager.Instance?.Process.Subscribe(ListenForNonClientClick).DisposeWith(handlerCleanup);
 
             var cleanupPopup = Disposable.Create((popupHost, handlerCleanup), state =>
             {
@@ -466,17 +457,17 @@ namespace Avalonia.Controls.Primitives
                     dismissLayer.IsVisible = true;
                     dismissLayer.InputPassThroughElement = _overlayInputPassThroughElement;
                     
-                    DeferCleanup(Disposable.Create(() =>
+                    Disposable.Create(() =>
                     {
                         dismissLayer.IsVisible = false;
                         dismissLayer.InputPassThroughElement = null;
-                    }));
+                    }).DisposeWith(handlerCleanup);
                     
-                    DeferCleanup(SubscribeToEventHandler<LightDismissOverlayLayer, EventHandler<PointerPressedEventArgs>>(
+                    SubscribeToEventHandler<LightDismissOverlayLayer, EventHandler<PointerPressedEventArgs>>(
                         dismissLayer,
                         PointerPressedDismissOverlay,
                         (x, handler) => x.PointerPressed += handler,
-                        (x, handler) => x.PointerPressed -= handler));
+                        (x, handler) => x.PointerPressed -= handler).DisposeWith(handlerCleanup);
                 }
             }
 
diff --git a/src/Avalonia.Controls/SystemDialog.cs b/src/Avalonia.Controls/SystemDialog.cs
index e74b950f23..d81926ecc7 100644
--- a/src/Avalonia.Controls/SystemDialog.cs
+++ b/src/Avalonia.Controls/SystemDialog.cs
@@ -4,30 +4,65 @@ using System.Linq;
 using System.Threading.Tasks;
 using Avalonia.Controls.Platform;
 
+#nullable enable
+
 namespace Avalonia.Controls
 {
+    /// <summary>
+    /// Base class for system file dialogs.
+    /// </summary>
     public abstract class FileDialog : FileSystemDialog
     {
+        /// <summary>
+        /// Gets or sets a collection of filters which determine the types of files displayed in an
+        /// <see cref="OpenFileDialog"/> or an <see cref="SaveFileDialog"/>.
+        /// </summary>
         public List<FileDialogFilter> Filters { get; set; } = new List<FileDialogFilter>();
-        public string InitialFileName { get; set; }        
+
+        /// <summary>
+        /// Gets or sets initial file name that is displayed when the dialog is opened.
+        /// </summary>
+        public string? InitialFileName { get; set; }        
     }
 
+    /// <summary>
+    /// Base class for system file and directory dialogs.
+    /// </summary>
     public abstract class FileSystemDialog : SystemDialog
     {
         [Obsolete("Use Directory")]
-        public string InitialDirectory
+        public string? InitialDirectory
         {
             get => Directory;
             set => Directory = value;
         }
-        public string Directory { get; set; }
+
+        /// <summary>
+        /// Gets or sets the initial directory that will be displayed when the file system dialog
+        /// is opened.
+        /// </summary>
+        public string? Directory { get; set; }
     }
 
+    /// <summary>
+    /// Represents a system dialog that prompts the user to select a location for saving a file.
+    /// </summary>
     public class SaveFileDialog : FileDialog
     {
-        public string DefaultExtension { get; set; }
+        /// <summary>
+        /// Gets or sets the default extension to be used to save the file (including the period ".").
+        /// </summary>
+        public string? DefaultExtension { get; set; }
 
-        public async Task<string> ShowAsync(Window parent)
+        /// <summary>
+        /// Shows the save file dialog.
+        /// </summary>
+        /// <param name="parent">The parent window.</param>
+        /// <returns>
+        /// A task that on completion contains the full path of the save location, or null if the
+        /// dialog was canceled.
+        /// </returns>
+        public async Task<string?> ShowAsync(Window parent)
         {
             if(parent == null)
                 throw new ArgumentNullException(nameof(parent));
@@ -37,11 +72,25 @@ namespace Avalonia.Controls
         }
     }
 
+    /// <summary>
+    /// Represents a system dialog that allows the user to select one or more files to open.
+    /// </summary>
     public class OpenFileDialog : FileDialog
     {
+        /// <summary>
+        /// Gets or sets a value indicating whether the user can select multiple files.
+        /// </summary>
         public bool AllowMultiple { get; set; }
 
-        public Task<string[]> ShowAsync(Window parent)
+        /// <summary>
+        /// Shows the open file dialog.
+        /// </summary>
+        /// <param name="parent">The parent window.</param>
+        /// <returns>
+        /// A task that on completion returns an array containing the full path to the selected
+        /// files, or null if the dialog was canceled.
+        /// </returns>
+        public Task<string[]?> ShowAsync(Window parent)
         {
             if(parent == null)
                 throw new ArgumentNullException(nameof(parent));
@@ -49,15 +98,27 @@ namespace Avalonia.Controls
         }
     }
 
+    /// <summary>
+    /// Represents a system dialog that allows the user to select a directory.
+    /// </summary>
     public class OpenFolderDialog : FileSystemDialog
     {
         [Obsolete("Use Directory")]
-        public string DefaultDirectory
+        public string? DefaultDirectory
         {
             get => Directory;
             set => Directory = value;
         }
-        public Task<string> ShowAsync(Window parent)
+
+        /// <summary>
+        /// Shows the open folder dialog.
+        /// </summary>
+        /// <param name="parent">The parent window.</param>
+        /// <returns>
+        /// A task that on completion returns the full path of the selected directory, or null if the
+        /// dialog was canceled.
+        /// </returns>
+        public Task<string?> ShowAsync(Window parent)
         {
             if(parent == null)
                 throw new ArgumentNullException(nameof(parent));
@@ -65,14 +126,32 @@ namespace Avalonia.Controls
         }
     }
 
+
+    /// <summary>
+    /// Base class for system dialogs.
+    /// </summary>
     public abstract class SystemDialog
     {
-        public string Title { get; set; }
+        /// <summary>
+        /// Gets or sets the dialog title.
+        /// </summary>
+        public string? Title { get; set; }
     }
 
+    /// <summary>
+    /// Represents a filter in an <see cref="OpenFileDialog"/> or an <see cref="SaveFileDialog"/>.
+    /// </summary>
     public class FileDialogFilter
     {
-        public string Name { get; set; }
+        /// <summary>
+        /// Gets or sets the name of the filter, e.g. ("Text files (.txt)").
+        /// </summary>
+        public string? Name { get; set; }
+
+        /// <summary>
+        /// Gets or sets a list of file extensions matched by the filter (e.g. "txt" or "*" for all
+        /// files).
+        /// </summary>
         public List<string> Extensions { get; set; } = new List<string>();
     }
 }
diff --git a/src/Avalonia.Input/Navigation/TabNavigation.cs b/src/Avalonia.Input/Navigation/TabNavigation.cs
index ed7df67bf2..c8290cb3b7 100644
--- a/src/Avalonia.Input/Navigation/TabNavigation.cs
+++ b/src/Avalonia.Input/Navigation/TabNavigation.cs
@@ -234,7 +234,7 @@ namespace Avalonia.Input.Navigation
             // Return the first visible element.
             var uiElement = e as InputElement;
 
-            if (uiElement is null || uiElement.IsVisible)
+            if (uiElement is null || IsVisibleAndEnabled(uiElement))
             {
                 if (e is IVisual elementAsVisual)
                 {
@@ -245,7 +245,7 @@ namespace Avalonia.Input.Navigation
                     {
                         if (children[i] is InputElement ie)
                         {
-                            if (ie.IsVisible)
+                            if (IsVisibleAndEnabled(ie))
                                 return ie;
                             else
                             {
@@ -270,7 +270,7 @@ namespace Avalonia.Input.Navigation
             // Return the last visible element.
             var uiElement = e as InputElement;
 
-            if (uiElement == null || uiElement.IsVisible)
+            if (uiElement == null || IsVisibleAndEnabled(uiElement))
             {
                 var elementAsVisual = e as IVisual;
 
@@ -283,7 +283,7 @@ namespace Avalonia.Input.Navigation
                     {
                         if (children[i] is InputElement ie)
                         {
-                            if (ie.IsVisible)
+                            if (IsVisibleAndEnabled(ie))
                                 return ie;
                             else
                             {
@@ -600,7 +600,7 @@ namespace Avalonia.Input.Navigation
                     var vchild = children[i];
                     if (vchild == elementAsVisual)
                         break;
-                    if (vchild.IsVisible == true && vchild is IInputElement ie)
+                    if (vchild is IInputElement ie && IsVisibleAndEnabled(ie))
                         prev = ie;
                 }
                 return prev;
@@ -668,5 +668,6 @@ namespace Avalonia.Input.Navigation
         }
 
         private static bool IsTabStopOrGroup(IInputElement e) => IsTabStop(e) || IsGroup(e);
+        private static bool IsVisibleAndEnabled(IInputElement e) => e.IsVisible && e.IsEnabled;
     }
 }
diff --git a/src/Windows/Avalonia.Direct2D1/Avalonia.Direct2D1.csproj b/src/Windows/Avalonia.Direct2D1/Avalonia.Direct2D1.csproj
index cda95d2ebb..8533e1e176 100644
--- a/src/Windows/Avalonia.Direct2D1/Avalonia.Direct2D1.csproj
+++ b/src/Windows/Avalonia.Direct2D1/Avalonia.Direct2D1.csproj
@@ -12,6 +12,7 @@
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\..\packages\Avalonia\Avalonia.csproj" />
+    <ProjectReference Include="..\Avalonia.Win32\Avalonia.Win32.csproj" />
   </ItemGroup>
   <Import Project="..\..\..\build\Rx.props" />
   <Import Project="..\..\..\build\SharpDX.props" />
diff --git a/src/Windows/Avalonia.Direct2D1/HwndRenderTarget.cs b/src/Windows/Avalonia.Direct2D1/HwndRenderTarget.cs
index 589f85f208..0597e88ed6 100644
--- a/src/Windows/Avalonia.Direct2D1/HwndRenderTarget.cs
+++ b/src/Windows/Avalonia.Direct2D1/HwndRenderTarget.cs
@@ -1,4 +1,5 @@
 using Avalonia.Platform;
+using Avalonia.Win32;
 using Avalonia.Win32.Interop;
 using SharpDX;
 using SharpDX.DXGI;
@@ -21,7 +22,7 @@ namespace Avalonia.Direct2D1
 
         protected override Size2F GetWindowDpi()
         {
-            if (UnmanagedMethods.ShCoreAvailable)
+            if (UnmanagedMethods.ShCoreAvailable && Win32Platform.WindowsVersion > PlatformConstants.Windows8)
             {
                 uint dpix, dpiy;
 
diff --git a/src/Windows/Avalonia.Win32.Interop/Wpf/Direct2DImageSurface.cs b/src/Windows/Avalonia.Win32.Interop/Wpf/Direct2DImageSurface.cs
index 5b04c5d7ff..bc0a399d7f 100644
--- a/src/Windows/Avalonia.Win32.Interop/Wpf/Direct2DImageSurface.cs
+++ b/src/Windows/Avalonia.Win32.Interop/Wpf/Direct2DImageSurface.cs
@@ -150,6 +150,7 @@ namespace Avalonia.Win32.Interop.Wpf
             if (_image == null || _oldDpi.X != dpi.X || _oldDpi.Y != dpi.Y)
             {
                 _image = new D3DImage(dpi.X, dpi.Y);
+                _oldDpi = dpi;
             }
             _impl.ImageSource = _image;
             
diff --git a/src/Windows/Avalonia.Win32/FramebufferManager.cs b/src/Windows/Avalonia.Win32/FramebufferManager.cs
index 699dc7c25d..0240ac9701 100644
--- a/src/Windows/Avalonia.Win32/FramebufferManager.cs
+++ b/src/Windows/Avalonia.Win32/FramebufferManager.cs
@@ -87,7 +87,7 @@ namespace Avalonia.Win32
 
         private Vector GetCurrentDpi()
         {
-            if (UnmanagedMethods.ShCoreAvailable)
+            if (UnmanagedMethods.ShCoreAvailable && Win32Platform.WindowsVersion > PlatformConstants.Windows8)
             {
                 var monitor =
                     UnmanagedMethods.MonitorFromWindow(_hwnd, UnmanagedMethods.MONITOR.MONITOR_DEFAULTTONEAREST);
diff --git a/src/Windows/Avalonia.Win32/PlatformConstants.cs b/src/Windows/Avalonia.Win32/PlatformConstants.cs
index af1eca29be..9dd4780637 100644
--- a/src/Windows/Avalonia.Win32/PlatformConstants.cs
+++ b/src/Windows/Avalonia.Win32/PlatformConstants.cs
@@ -1,8 +1,13 @@
+using System;
+
 namespace Avalonia.Win32
 {
-    static class PlatformConstants
+    public static class PlatformConstants
     {
         public const string WindowHandleType = "HWND";
         public const string CursorHandleType = "HCURSOR";
+
+        public static readonly Version Windows8 = new Version(6, 2);
+        public static readonly Version Windows7 = new Version(6, 1);
     }
 }
diff --git a/src/Windows/Avalonia.Win32/SystemDialogImpl.cs b/src/Windows/Avalonia.Win32/SystemDialogImpl.cs
index ad81cc1778..f595a58c91 100644
--- a/src/Windows/Avalonia.Win32/SystemDialogImpl.cs
+++ b/src/Windows/Avalonia.Win32/SystemDialogImpl.cs
@@ -19,7 +19,7 @@ namespace Avalonia.Win32
             var hWnd = parent?.PlatformImpl?.Handle?.Handle ?? IntPtr.Zero;
             return Task.Factory.StartNew(() =>
             {
-                var result = Array.Empty<string>();
+                string[] result = default;
 
                 Guid clsid = dialog is OpenFileDialog ? UnmanagedMethods.ShellIds.OpenFileDialog : UnmanagedMethods.ShellIds.SaveFileDialog;
                 Guid iid = UnmanagedMethods.ShellIds.IFileDialog;
@@ -100,7 +100,7 @@ namespace Avalonia.Win32
         {
             return Task.Factory.StartNew(() =>
             {
-                string result = string.Empty;
+                string result = default;
 
                 var hWnd = parent?.PlatformImpl?.Handle?.Handle ?? IntPtr.Zero;
                 Guid clsid = UnmanagedMethods.ShellIds.OpenFileDialog;
@@ -164,7 +164,7 @@ namespace Avalonia.Win32
                     }
                 }
             }
-            return "";
+            return default;
         }
     }
 }
diff --git a/src/Windows/Avalonia.Win32/Win32GlManager.cs b/src/Windows/Avalonia.Win32/Win32GlManager.cs
index e159ba3b78..e70ea52106 100644
--- a/src/Windows/Avalonia.Win32/Win32GlManager.cs
+++ b/src/Windows/Avalonia.Win32/Win32GlManager.cs
@@ -1,4 +1,3 @@
-using System;
 using Avalonia.OpenGL;
 using Avalonia.OpenGL.Angle;
 using Avalonia.OpenGL.Egl;
@@ -9,7 +8,6 @@ namespace Avalonia.Win32
 {
     static class Win32GlManager
     {
-        private static readonly Version Windows7 = new Version(6, 1);
 
         public static void Initialize()
         {
@@ -22,7 +20,7 @@ namespace Avalonia.Win32
                     return wgl;
                 }
 
-                if (opts?.AllowEglInitialization ?? Win32Platform.WindowsVersion > Windows7)
+                if (opts?.AllowEglInitialization ?? Win32Platform.WindowsVersion > PlatformConstants.Windows7)
                 {
                     var egl = EglPlatformOpenGlInterface.TryCreate(() => new AngleWin32EglDisplay());
 
diff --git a/src/Windows/Avalonia.Win32/Win32Platform.cs b/src/Windows/Avalonia.Win32/Win32Platform.cs
index a881c45cd0..c011a458c3 100644
--- a/src/Windows/Avalonia.Win32/Win32Platform.cs
+++ b/src/Windows/Avalonia.Win32/Win32Platform.cs
@@ -94,7 +94,7 @@ namespace Avalonia
 
 namespace Avalonia.Win32
 {
-    class Win32Platform : IPlatformThreadingInterface, IPlatformSettings, IWindowingPlatform, IPlatformIconLoader, IPlatformLifetimeEventsImpl
+    public class Win32Platform : IPlatformThreadingInterface, IPlatformSettings, IWindowingPlatform, IPlatformIconLoader, IPlatformLifetimeEventsImpl
     {
         private static readonly Win32Platform s_instance = new Win32Platform();
         private static Thread _uiThread;
diff --git a/src/Windows/Avalonia.Win32/WindowImpl.cs b/src/Windows/Avalonia.Win32/WindowImpl.cs
index 0b7bd13082..3b7d3efa2f 100644
--- a/src/Windows/Avalonia.Win32/WindowImpl.cs
+++ b/src/Windows/Avalonia.Win32/WindowImpl.cs
@@ -764,8 +764,8 @@ namespace Avalonia.Win32
                 RegisterTouchWindow(_hwnd, 0);
             }
 
-            if (ShCoreAvailable)
-            {
+            if (ShCoreAvailable && Win32Platform.WindowsVersion > PlatformConstants.Windows8)
+			{
                 var monitor = MonitorFromWindow(
                     _hwnd,
                     MONITOR.MONITOR_DEFAULTTONEAREST);
diff --git a/tests/Avalonia.Controls.UnitTests/Utils/HotKeyManagerTests.cs b/tests/Avalonia.Controls.UnitTests/Utils/HotKeyManagerTests.cs
index 2a3db9992c..b0eb694944 100644
--- a/tests/Avalonia.Controls.UnitTests/Utils/HotKeyManagerTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Utils/HotKeyManagerTests.cs
@@ -10,7 +10,6 @@ using Avalonia.Styling;
 using Avalonia.UnitTests;
 using Moq;
 using Xunit;
-using System;
 using Avalonia.Input.Raw;
 using Factory = System.Func<int, System.Action<object>, Avalonia.Controls.Window, Avalonia.AvaloniaObject>;
 
diff --git a/tests/Avalonia.Input.UnitTests/KeyboardDeviceTests.cs b/tests/Avalonia.Input.UnitTests/KeyboardDeviceTests.cs
index 7730cee78c..c354dbe72e 100644
--- a/tests/Avalonia.Input.UnitTests/KeyboardDeviceTests.cs
+++ b/tests/Avalonia.Input.UnitTests/KeyboardDeviceTests.cs
@@ -2,7 +2,6 @@
 using System.Windows.Input;
 using Avalonia.Controls;
 using Avalonia.Input.Raw;
-using Avalonia.Interactivity;
 using Avalonia.UnitTests;
 using Moq;
 using Xunit;
@@ -126,7 +125,7 @@ namespace Avalonia.Input.UnitTests
         {
             private readonly Action _action;
             public DelegateCommand(Action action) => _action = action;
-            public event EventHandler CanExecuteChanged;
+            public event EventHandler CanExecuteChanged { add { } remove { } }
             public bool CanExecute(object parameter) => true;
             public void Execute(object parameter) => _action();
         }
diff --git a/tests/Avalonia.Input.UnitTests/KeyboardNavigationTests_Tab.cs b/tests/Avalonia.Input.UnitTests/KeyboardNavigationTests_Tab.cs
index edcbf75a1d..9a117bb71d 100644
--- a/tests/Avalonia.Input.UnitTests/KeyboardNavigationTests_Tab.cs
+++ b/tests/Avalonia.Input.UnitTests/KeyboardNavigationTests_Tab.cs
@@ -1225,5 +1225,32 @@ namespace Avalonia.Input.UnitTests
                 "Button2", "Button3", "Button5", "Button1", "Button6", "Button4"
             }, result);
         }
+
+        [Fact]
+        public void Cannot_Focus_Child_Of_Disabled_Control()
+        {
+            Button start;
+            Button expected;
+
+            var top = new StackPanel
+            {
+                [KeyboardNavigation.TabNavigationProperty] = KeyboardNavigationMode.Cycle,
+                Children =
+                {
+                    (start = new Button { Name = "Button1" }),
+                    new Border
+                    {
+                        IsEnabled = false,
+                        Child = new Button { Name = "Button2" },
+                    },
+                    (expected = new Button { Name = "Button3" }),
+                }
+            };
+
+            var current = (IInputElement)start;
+            var result = KeyboardNavigationHandler.GetNext(current, NavigationDirection.Next);
+
+            Assert.Same(expected, result);
+        }
     }
 }
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/DynamicResourceExtensionTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/DynamicResourceExtensionTests.cs
index e7f0230254..592dbfc0d1 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/DynamicResourceExtensionTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/DynamicResourceExtensionTests.cs
@@ -923,7 +923,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
         public bool HasResources => true;
         public List<object> RequestedResources { get; } = new List<object>();
 
-        public event EventHandler OwnerChanged;
+        public event EventHandler OwnerChanged { add { } remove { } }
 
         public void AddOwner(IResourceHost owner) => Owner = owner;
         public void RemoveOwner(IResourceHost owner) => Owner = null;