WebKit.NET component not working correctly

Question

I'm trying to make basic webbrowser in C# in Visual Studio, but I won't use built-in webbrowser component with IE rendering engine. So I downloaded WebKit.NET and added to my project. But it can load only one page - google.com. So when I put google.com to textbox and then press button, it works. But if I put to textbox else adress (toutube.com, facebook.com,...) it does nothing. With buit-in webbrowser everything works fine, but still on IE engine. Where can be mistake? The code is:

private void button1_Click(object sender, EventArgs e)
        {
            webkitBrowser1.Navigate(textBox1.Text);
        }