I have a WPF window in a VSIX application that I show as follows:
var myWindow = new MyWindow(this.CurrentWorkspace)
Owner = Application.Current.MainWindow
Microsoft Visual Studio has detected that an operation is blocking
user input. This can be caused by an active modal dialog or a task
that needs to block user interaction.
Found that the DialogWindow solved the problem mentioned, but it wasn't a complete solution. Refer to: WPF modal window in Visual Studio Extension blocking input.