def _on_apply_button_clicked(self, *args):
        """Apply button clicked: Apply the configuration
        """
        refresh_required = self.core_config_model.apply_preliminary_config()
        refresh_required |= self.gui_config_model.apply_preliminary_config()

        if not self.gui_config_model.config.get_config_value("SESSION_RESTORE_ENABLED"):
            import rafcon.gui.backup.session as backup_session
            logger.info("Removing current session")
            backup_session.reset_session()
        if refresh_required:
            from rafcon.gui.singleton import main_window_controller
            main_window_controller.get_controller('menu_bar_controller').on_refresh_all_activate(None, None)
        self._popup_message()