The current Xamarin Forms master detail template is broken. You will get an error like Error CS0101 The namespace 'already contains a definition for

The fix..(thank you Kym Phillpotts)

1. It would appear, that the added pages have the wrong namespace. So change the namespace on the added pages

• Page1.xaml.cs - change the Namespace to be just MyApp
• Page1Detail.xaml.cs - Change the namespace to be just MyApp
• Page1Master.xaml.cs - Change the namespace to be just MyApp
• Page1MenuItem.cs - Change the namespace to "MyApp"

2. I also noticed that in the Page1Master.xaml.cs it is incorrectly referencing the MenuItems. It says Page1MenuItems = new ObservableCollection...Change that to be justMenuItems = new ObservableCollection...

No you can go to your App.Xaml.xs and set the Page1 as the master page:

eg.MainPage = new MyApp.Page1()

Reference: https://forums.xamarin.com/discussion/89346/forms-master-detail-page-generation-is-broken

Also there are bugs in Bugzilla for both of these:
https://bugzilla.xamarin.com/show_bug.cgi?id=53020https://bugzilla.xamarin.com/show_bug.cgi?id=53021