Did you removed the
StartupUri attribute from the App.xaml file? You are manually instantiating the
Shell window in your Bootstrapper class, so this attribute is not required.
To remove the
StartupUri attribute follow this steps:
Open the App.xaml file located in the project that contains the Shell.
Remove the following attribute in the XAML:
The code in the App.xaml file should look like the following:
Please, let me know if it helps.