Xamarin Forms Xaml with Android

Hi,
I'm using Xaml to create to my UI in Xamarin Forms for Android project. I'm targeting API Level 16 for it.
But when I run the project I get some "Runtime Exception" called System.NullReferenceException:Loading

See the attached screen shot

Using all latest version of Xamarin and Forms

The Xaml Markup is below

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="XamForms.Core.MyPage">
    <ContentPage.Content>
        <StackLayout Orientation="Horizontal">
            <Label Text="Hello World" />
        </StackLayout>
    </ContentPage.Content>
</ContentPage>

Please help

Thanks
Goldy