The tag 'XXX' does not exist in XML namespace 'clr-namespace:YYY'

Question

I have implemented a converter to convert Int32 to String to be able to binding a property to a textBox.

I implement this converter in the namespace MyApp.Converters and

Answer 1

All answers are right. And after trying all of them and you cannot configure why its happening, everything seems alright, Please restart the Visual studio.

That worked for me after wasting almost 1 hour. I found everything ok, but restarted the VS with administration.