exception while navigating webbrowser in WPF MVVM

Hi,

I am getting exception 'The requested resource is in use. (Exception from HRESULT: 0x800700AA)', while trying to navigate web browser control in the below code. please suggest, how to solve this error.

public void WebBrowser_LoadCompleted(object sender, NavigationEventArgs n)
        {
            MyWebBrowser.Navigate(new Uri(ModelObject.OnSelectionChangedInGrid(MyWebBrowser.Source, datagrid.SelectedIndex), UriKind.Absolute));
            OnWebBrowserLoadCompleted((HTMLDocumentClass)MyWebBrowser.Document);

        }