Suggestion: Suppress benign WMC1501 warning.

[Noemata]

Since the WMC1501 warning is benign, you may want to add the following pragma to App.xaml.cs in NotificationFlyoutSample.Host.csproj:

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;

namespace NotificationFlyoutSample.Host
{
// No need to report benign warning.
#pragma warning disable WMC1501
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : Application
    {
    }
}

I'm not sure about the other two warnings I'm seeing, WMC1006 and MSB3277. These might not be so innocent.

[Noemata]

Sorry, made a mistake in the module above. And the pragma doesn't work, hmmm (should have tried it first).