Universal app on Windows Phone 10 black screen

Question

Hello,
I received strange feedback that my application has some problems on Windows Phone 10. I can't test this because I don't have any Win10 devices. Can anyone check this app:
https://www.windowsphone.com/en-us/store/app/instabullet/28cffcfa-4568-45e5-820d-fb761b408bdd?signin=true
I have no idea where is the problem. After application starts it loads WebView with login page and on Win10 it is only black screen - at least one user has this problem with Lumia 635. Anyone had similiar problems? It is said that Universal app should work
on Win10 if they work on Win 8.1.

Answer 1

It's a simple page with WebView, frameworks used are Unity, MVVM light.
XAML:
<Page
x:Class="PushBulletClient.Views.WebAuthView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:PushBulletClient"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:utils="using:PushBulletClient.Utils"
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
DataContext="{Binding WebAuthViewModel, Source={StaticResource Locator}}"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
xmlns:controls="using:PushBulletClient.Controls"
xmlns:interactivity="using:Microsoft.Xaml.Interactivity"
xmlns:core="using:Microsoft.Xaml.Interactions.Core">
<Grid x:Name="LayoutRoot" Background="{StaticResource BackgroundColor}">
<Grid.ChildrenTransitions>
<TransitionCollection>
<EntranceThemeTransition/>
</TransitionCollection>
</Grid.ChildrenTransitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<!-- Title Panel -->
<controls:HeaderControl Header="Login" IconSource="{StaticResource LogoImage}"/>
<!--TODO: Content should be placed within the following grid-->
<Grid Grid.Row="1" x:Name="ContentRoot" Margin="19,9.5,19,0">
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid x:Name="GridLoading" Visibility="{Binding State,
Converter={StaticResource StateIsEqualConverter},ConverterParameter=Loading}"
Grid.Row="0" >
<StackPanel HorizontalAlignment="Stretch" VerticalAlignment="Center">
<ProgressBar HorizontalAlignment="Stretch" Background="{StaticResource BackgroundColor}" IsIndeterminate="True" />
<TextBlock HorizontalAlignment="Center" Text="Loading..." />
</StackPanel>
</Grid>
<Grid x:Name="GridDeclined" Visibility="{Binding State,
Converter={StaticResource StateIsEqualConverter},ConverterParameter=Declined}"
Grid.Row="0" >
<StackPanel Orientation="Vertical">
<TextBlock Margin="0,0,0,20" Style="{StaticResource SubheaderTextBlockStyle}" Text="Declined"/>
<TextBlock TextWrapping="Wrap" Text="You must allow access to use Instabullet."/>
<Button Margin="0,10,0,0" Content="Back" Click="ButtonBack_OnClick"/>
</StackPanel>
</Grid>
<WebView Grid.Row="0"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
x:Name="Navigator"
NavigationStarting="Navigator_OnNavigationStarting"
Visibility="{Binding IsBrowserVisible, Converter={StaticResource BoolToVisibilityConverter}}"
>
<interactivity:Interaction.Behaviors>
<core:EventTriggerBehavior EventName="NavigationStarting">
<core:InvokeCommandAction Command="{Binding NavigationStartingCommand}"
InputConverter="{StaticResource StartingArgsToWebNavigationResultConverter}" />
</core:EventTriggerBehavior>
<core:EventTriggerBehavior EventName="NavigationCompleted">
<core:InvokeCommandAction Command="{Binding NavigationCompletedCommand}"
InputConverter="{StaticResource CompletedArgsToWebNavigationResultConverter}" />
</core:EventTriggerBehavior>
</interactivity:Interaction.Behaviors>
</WebView>
</Grid>
</Grid>
</Page>
CS
using System;
using Windows.Foundation;
using Windows.Phone.UI.Input;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;
using GalaSoft.MvvmLight;
using PushBulletClient.Common;
// The Basic Page item template is documented at http://go.microsoft.com/fwlink/?LinkID=390556
using PushBulletClient.Contracts.ViewModels;
using PushBulletClient.Contracts.Views;
using PushBulletClient.Models;
using PushBulletClient.Utils;
using PushBulletClient.ViewModels;
namespace PushBulletClient.Views
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class WebAuthView : Page, IView
private NavigationHelper navigationHelper;
private ObservableDictionary defaultViewModel = new ObservableDictionary();
public WebAuthView()
this.InitializeComponent();
this.navigationHelper = new NavigationHelper(this);
this.navigationHelper.LoadState += NavigationHelper_LoadState;
this.navigationHelper.SaveState += NavigationHelper_SaveState;
this.Unloaded += WebAuthView_Unloaded;
HardwareButtons.BackPressed += HardwareButtons_BackPressed;
Navigator.Navigate(new Uri(Consts.AppUri));
void WebAuthView_Unloaded(object sender, RoutedEventArgs e)
HardwareButtons.BackPressed -= HardwareButtons_BackPressed;
/// <summary>
/// Gets the <see cref="NavigationHelper"/> associated with this <see cref="Page"/>.
/// </summary>
public NavigationHelper NavigationHelper
get { return this.navigationHelper; }
/// <summary>
/// Gets the view model for this <see cref="Page"/>.
/// This can be changed to a strongly typed view model.
/// </summary>
public ObservableDictionary DefaultViewModel
get { return this.defaultViewModel; }
/// <summary>
/// Populates the page with content passed during navigation. Any saved state is also
/// provided when recreating a page from a prior session.
/// </summary>
/// <param name="sender">
/// The source of the event; typically <see cref="NavigationHelper"/>
/// </param>
/// <param name="e">Event data that provides both the navigation parameter passed to
/// <see cref="Frame.Navigate(Type, Object)"/> when this page was initially requested and
/// a dictionary of state preserved by this page during an earlier
/// session. The state will be null the first time a page is visited.</param>
private void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
/// <summary>
/// Preserves state associated with this page in case the application is suspended or the
/// page is discarded from the navigation cache. Values must conform to the serialization
/// requirements of <see cref="SuspensionManager.SessionState"/>.
/// </summary>
/// <param name="sender">The source of the event; typically <see cref="NavigationHelper"/></param>
/// <param name="e">Event data that provides an empty dictionary to be populated with
/// serializable state.</param>
private void NavigationHelper_SaveState(object sender, SaveStateEventArgs e)
#region NavigationHelper registration
/// <summary>
/// The methods provided in this section are simply used to allow
/// NavigationHelper to respond to the page's navigation methods.
/// <para>
/// Page specific logic should be placed in event handlers for the
/// <see cref="NavigationHelper.LoadState"/>
/// and <see cref="NavigationHelper.SaveState"/>.
/// The navigation parameter is available in the LoadState method
/// in addition to page state preserved during an earlier session.
/// </para>
/// </summary>
/// <param name="e">Provides data for navigation methods and event
/// handlers that cannot cancel the navigation request.</param>
protected override void OnNavigatedTo(NavigationEventArgs e)
Navigator.Refresh();
this.navigationHelper.OnNavigatedTo(e);
protected override void OnNavigatedFrom(NavigationEventArgs e)
this.navigationHelper.OnNavigatedFrom(e);
#endregion
public ViewModelBase ViewModel
get { return this.DataContext as ViewModelBase; }
private void HardwareButtons_BackPressed(object sender, BackPressedEventArgs e)
if (Navigator.CanGoBack)
Navigator.GoBack();
e.Handled = true;
private void Navigator_OnNavigationStarting(WebView sender, WebViewNavigationStartingEventArgs args)
if (args.Uri.AbsolutePath.Contains("blank"))
Navigator.Navigate(new Uri(Consts.AppUri));
private void ButtonBack_OnClick(object sender, RoutedEventArgs e)
Navigator.Navigate(new Uri(Consts.AppUri));
There is also logic in ViewModel which doesn't contain any specific logic.