Chat/PrototypChat/App.xaml.cs

using System;
using System.Threading.Tasks;
using System.Windows;

namespace ownChat
{
    public partial class App
    {
        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);

            SetupExceptionHandling();
        }

        private void SetupExceptionHandling()
        {
            AppDomain.CurrentDomain.UnhandledException += (s, e) =>
            {
                new ExceptionWindow((Exception) e.ExceptionObject) { Owner = MainWindow }.Show();
            };

            DispatcherUnhandledException += (s, e) =>
            {
                new ExceptionWindow(e.Exception) { Owner = MainWindow }.Show();

                e.Handled = true;
            };

            TaskScheduler.UnobservedTaskException += (s, e) =>
            {
                new ExceptionWindow(e.Exception) { Owner = MainWindow }.Show();
                e.SetObserved();
            };
        }
    }
}