getting exception on xamarin.forms

I am trying to build my crossplatform application but when I try to run it on android emulator, on LoadApplication(new App()) I keep getting an exception.

at Xamarin.Forms.Platform.Android.MasterDetailRenderer.SetElement (Xamarin.Forms.VisualElement element) [0x0008f] in C:BuildAgent2workaad494dc9bc9783Xamarin.Forms.Platform.AndroidRenderersMasterDetailRenderer.cs:93 at Xamarin.Forms.Platform.Android.Platform.CreateRenderer (Xamarin.Forms.VisualElement element) [0x0001f] in C:BuildAgent2workaad494dc9bc9783Xamarin.Forms.Platform.AndroidPlatform.cs:284 at Xamarin.Forms.Platform.Android.Platform.AddChild (Xamarin.Forms.VisualElement view, Boolean layout) [0x00015] in C:BuildAgent2workaad494dc9bc9783Xamarin.Forms.Platform.AndroidPlatform.cs:520 at Xamarin.Forms.Platform.Android.Platform.SetPage (Xamarin.Forms.Page newRoot) [0x00089] in C:BuildAgent2workaad494dc9bc9783Xamarin.Forms.Platform.AndroidPlatform.cs:408 at Xamarin.Forms.Platform.Android.FormsApplicationActivity.InternalSetPage (Xamarin.Forms.Page page) [0x000b7] in C:BuildAgent2workaad494dc9bc9783Xamarin.Forms.Platform.AndroidFormsApplicationActivity.cs:288 at Xamarin.Forms.Platform.Android.FormsApplicationActivity.SetMainPage () [0x00000] in C:BuildAgent2workaad494dc9bc9783Xamarin.Forms.Platform.AndroidFormsApplicationActivity.cs:307 at Xamarin.Forms.Platform.Android.FormsApplicationActivity.LoadApplication (Xamarin.Forms.Application application) [0x0003f] in C:BuildAgent2workaad494dc9bc9783Xamarin.Forms.Platform.AndroidFormsApplicationActivity.cs:110 at Giftolic.Mobile.Droid.MainActivity.OnCreate (Android.OS.Bundle bundle) [0x00028] in C:ProjectsGiftolic.MobileGiftolic.MobileGiftolic.Mobile.DroidMainActivity.cs:33

by the way there is no error on build and I already updated all the libraries.