It seems that when using DisplayRootViewFor<T>(), the RegisterNavigationService (on PrepareViewFirst) method is not called and you end up with null passed in for the INavigationService.
This didn't happen on the previous version.
Comments: This is by design, DisplayRootViewFor<T>() is for enabling a view model first approach. The expectation is that you would be creating your own root view model that would work as a conductor. Using DisplayRootView<T>() enables a view first approach similar to Windows Phone where Caliburn Micro handles some of the work of the conductor by creating a Root Frame and enabling the navigation service.
This didn't happen on the previous version.
Comments: This is by design, DisplayRootViewFor<T>() is for enabling a view model first approach. The expectation is that you would be creating your own root view model that would work as a conductor. Using DisplayRootView<T>() enables a view first approach similar to Windows Phone where Caliburn Micro handles some of the work of the conductor by creating a Root Frame and enabling the navigation service.