Undefined CLR namespace

Question

I have the following:

The error says The \'clr-namespace\' URI refers to a na

Answer 1

I had the same error message given to me. But the underlying problem was different. I moved my MainWindow.xaml to a different folder, and I forgot to update my App.xaml StartupUri. I then updated my StartupUri in my App.xaml and the problem was fixed.