WPF app with WebBrowser closes automatically

I need to add WebBrowser control to WPF form.

I have the easiest code:

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525" Loaded="Window_Loaded">
    <Grid>
        <WebBrowser HorizontalAlignment="Left" Height="279" Margin="10,10,0,0" Name="wb1" VerticalAlignment="Top" Width="461">
        </WebBrowser>

    </Grid>
</Window>


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication2
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        string url = "http://www.microsoft.com";
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            wb1.Source = new Uri(url);
        }
    }
}

but application is closing automatically navigate to page. Why?

I see the following strings on output code:

The program '[4892] WpfApplication5.vshost.exe: Program Trace' has exited with code 0 (0x0). The program '[4892] WpfApplication5.vshost.exe: Managed (v4.0.30319)' has exited with code -1073740791 (0xc0000409).

I fixed this problem (but only for Visual Studio 2010, project under Visual Studio 2013 has error) - I have changed "Target Platform" from x86 to "Any CPU". Strange, but works