Problems creating backup

I'm trying to generate the backup of a course, but this is not generated with the files you have. 

I'm using the following code:

$bc = new backup_controller(backup::TYPE_1COURSE, $template->id, backup::FORMAT_MOODLE,

                        backup::INTERACTIVE_NO, backup::MODE_IMPORT, $USER->id);

      $backupid       = $bc->get_backupid();

      $backupbasepath = $bc->get_plan()->get_basepath();

      $bc->execute_plan();

      $bc->destroy();