We have an application that was developed using .NET 4.8 and the Visual Studio 2015 Shell (Isolated). This application is now crashing whenever a tool window is docked following the update to KB4601050.
I have tried adding the switches to the app.config file as indicated in the KB article, but it has no effect.
<configuration>
<runtime>
<AppContextSwitchOverrides value="Switch.System.Windows.Interop.MouseInput.OptOutOfMoveToChromedWindowFix=true; Switch.System.Windows.Interop.MouseInput.DoNotOptOutOfMoveToChromedWindowFix=true" />
</runtime>
</configuration>
What options do I have to remedy this situation?
Application: xxxxx.exe Framework Version: v4.0.30319 Description: The process was terminated due to an unhandled exception. Exception Info: System.NullReferenceException at System.Windows.Interop.HwndMouseInputProvider.HasCustomChrome(System.Windows.Interop.HwndSource, RECT ByRef) at System.Windows.Interop.HwndMouseInputProvider.GetEffectiveClientRect(IntPtr) at System.Windows.Interop.HwndMouseInputProvider.PossiblyDeactivate(IntPtr, Boolean) at System.Windows.Interop.HwndMouseInputProvider.Dispose() at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr, MS.Internal.Interop.WindowMessage, IntPtr, IntPtr, Boolean ByRef) at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef) at MS.Win32.HwndWrapper.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef) at MS.Win32.HwndSubclass.DispatcherCallbackOperation(System.Object) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate) at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(System.Windows.Threading.DispatcherPriority, System.TimeSpan, System.Delegate, System.Object, Int32) at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)
Although I was unable to resolve the issue by adding the switches to the app.config file, adding them to the registry resolved the issue. However, note that the registry path indicated in the article https://learn.microsoft.com/en-us/dotnet/api/system.appcontext?view=netcore-3.1#remarks is missing a slash between Microsoft and .NETFramework.