I get an error and my app crashes when I do this.

 private void ExecuteBarCodeLabels(object parameter)

        {
            IsBusy = true;
            SetUpBarCodeLabelsCommand.ProcessLabels(_batchId,"SLS01" ,(o, e) =>
                                           {
                                               if (e.Object != null && e.Error == null)
                                               {
                                                   IsBusy = false;
 
                                                   NavigationCommands.Navigate.Execute(new Uri("http://abracadabrareports.easylib.co.uk/webform1.aspx", UriKind.Absolute),(UIElement)ISFocusManager.GetFocusedElement());
                                               }
                                               else
                                               {
                                                   IsBusy = false;
 
                                                   Utils.LogError(string.Format("{0}\n\nError found in: {1}", e.Error != null ? e.Error.Message : "Unknown Error", "SetUpBarCodeLabelsCommand:ProcessLabels"), true);
                                               }
                                           });
        }

  It creashes on

NavigationCommands.Navigate.Execute(new Uri("http://abracadabrareports.easylib.co.uk/webform1.aspx", UriKind.Absolute),(UIElement)ISFocusManager.GetFocusedElement());

I am trying to run some db code (inserts) then navigate to an external (new) web page - can you please advise - thanks