The name "ContentPage" does not exist in the namespace "http://xamarin.com/schemas/2014/form

Hi
I am new to Xamarin Windows Phone App. How to solve this Error. I am using Shared Code project. I am just calling the Forms(Xaml Page) Through Shared Project Reference For Windows Phone. The Error is "The name "ContentPage" does not exist in the namespace http://xamarin.com/schemas/2014/forms".

Here i have attached the Xaml code here. Kindly Help me out. Thanks in Advance.