how to fix the blank listview page in xamarin

Question

Hello my lists have turned white I do not have an error message and the deployment fails. I saw somewhere that it happened when we first created the items or the opposite I do not know anymore. Maybe I do not create the classes the right way Thank you

enter code here

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
         xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
         x:Class="jaune.Views.ContactPage">
<ContentPage.Content>
    <StackLayout Orientation="Vertical" >
        <Label Text="page des contacts" HorizontalOptions="Center"/>
       <ScrollView>
            <StackLayout HeightRequest="400">                    
                <ListView x:Name="ListContact" >
                    <ListView.ItemTemplate>
                        <DataTemplate>
                            <ViewCell>
                                <StackLayout Orientation="Horizontal" 
BackgroundColor="Gray" VerticalOptions="Center" Margin="25,0" 
Padding="10">
                                    <Image Source="carre"/>
                                    <Label Text="{Binding Nom}"/>
                                    <Label Text="{Binding Prenom}"/>
                                </StackLayout>
                            </ViewCell>
                        </DataTemplate>
                    </ListView.ItemTemplate>
                 </ListView>
            </StackLayout>
       </ScrollView>
        <StackLayout VerticalOptions="End">
            <Label Text="Lorsque X personnes auront validé votre 
proposition vos contacts pourront partager votre idée"
                   HorizontalOptions="Center"
                   Margin="15" FontSize="20"/>
            <Label Text=" X contact minimum" HorizontalOptions="Center"/>
            <Button Text="valider"/>
    </StackLayout>
    </StackLayout>
</ContentPage.Content>
</ContentPage>

I dont know if i use the good way to make a list view

namespace jaune.Views
{
    [XamlCompilation(XamlCompilationOptions.Compile)]
     public class Contact
        {
          public string Nom { get; set; }
          public string Prenom { get; set; }
        }
    public partial class ContactPage : ContentPage
    {
        List<Contact> contacts;
        public ContactPage()
        {

            InitializeComponent();

            contacts = new List<Contact>
            {
                new Contact { Nom = "le roi", Prenom = "Arthur" },
                new Contact { Nom = "Deja ", Prenom = "Boyd" },
                new Contact { Nom = "Jairo ", Prenom = "Alvarez" },
                new Contact { Nom = "Kaylee ", Prenom = "Spence" },
                new Contact { Nom = "Hana ", Prenom = "Ponce" },
                new Contact { Nom = "Aubree  ", Prenom = "Lynch" },
                new Contact { Nom = "Logan  ", Prenom = "Knight" },
                new Contact { Nom = "Caitlyn  ", Prenom = "Davila" },
                new Contact { Nom = "Elisha ", Prenom = "Howell" },
                new Contact { Nom = "Rayan  ", Prenom = "Moyer" },
                new Contact { Nom = "Harper  ", Prenom = "Summers" },
                new Contact { Nom = "Natalia  ", Prenom = "Jefferson" },
                new Contact { Nom = "Olive  ", Prenom = "Ponce" },
                new Contact { Nom = "Adan   ", Prenom = "Wilkerson" },
                new Contact { Nom = "Logan  ", Prenom = "Knight" },
                new Contact { Nom = "Darren   ", Prenom = "Mack" }
            };

            ListContact.ItemsSource = contacts;
        }
    }
}

Finally the solution was to return to VS 2017