The Working page of the Group Apply Wizard is displayed by the wizard whilst the permissions are being applied to the selected object:
The bar gives an indication of how much progress the wizard has made and once enough objects have been processed, an estimate of the remaining time will be displayed. If necessary, click the Cancel button to stop the wizard and return to the Confirmation page. When the wizard has completed, the Finished page will be displayed.
Note If you cancel the wizard, any changes already applied will not be reversed.