C++/WinRT basic two way binding error.

Question

Error C3779 'winrt::Windows::UI::Xaml::Data::PropertyChangedEventHandler::operator ()': a function that returns 'auto' cannot be used before it is defined MVVMTest C:\Users\synap\source\repos\MVVMTest\MVVMTest\Generated Files\winrt\base.h 5762

Built a basic project using the new Windows App SDK and I get this error when I try to build. I followed the instructions in the Binding in depth found in the docs and put everything on the main page as I could not get the full setup with the HostViewModel working. What am I implementing incorrectly?

This is a very simple setup so there is not much code to look at.

Thank you ahead of time.

Link to git:
https://github.com/synapse187/MVVMTest.git