возникает ошибка при открытии карт в браузере в windows forms

public partial class Form3 : Form
{
    public Form3()
    {
        InitializeComponent();
    }
    private void gMapControl1_Load(object sender, EventArgs e)
    {
    }
    private void button1_Click(object sender, EventArgs e)
    {
        string textbox1 = textBox1.Text;
        string textbox2 = textBox2.Text;
        try
        {
            StringBuilder queryaddress = new StringBuilder();
            queryaddress.Append("https://www.google.by/maps/@53.9770381,30.4071148,4232m/data=!3m1!1e3?hl=ru&entry=ttu");
            if (textbox1 != string.Empty)
            {
                queryaddress.Append(textBox1 + "," + "+");
            }
            if (textbox2 != string.Empty)
            {
                queryaddress.Append(textbox2 + "," + "+");
            }
            webBrowser1.Navigate(queryaddress.ToString());
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message.ToString(), "Error");
        }
    }

    private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
    {

    }

    private void splitContainer1_Panel1_Paint(object sender, PaintEventArgs e)
    {

    }
}

}