Go ahead and add [STAThread] to the main entry of your application, this indicates the COM threading model is single-threaded apartment (STA)
example:
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new WebBrowser());
}
}