Kim Hornung

We’re still getting the “Invalid JSON” error emails, despite having cleared our caches and resetting the Scheduler on the debug page.

Our manual scans work.

The problem is not related to PHP version (I’m on PHP 8.2).

The problem happens if using the built-in WP cron. You can manually trigger this by accessing this URL:
http://<hostname>/wp-cron.php?doing_wp_cron

Then you should (hopefully) see the warning in the debug.log file. But let me know if you don’t, then I’ll be happy to see if I can provide additional troubleshooting steps.

I’m also seeing this warning in the debug.log file after upgrading to the most recent NS Cloner version and WP 6.6.1.

It seems that the NS Cloner’s register_interval() hook is not active when wp-cron.php calls wp_reschedule_event()

I have also encountered this problem, and I’ve found a workaround for it.

The problem is that the plugin’s ‘cron_schedules’ hook is initialized in the Inpsyde_PhoneHome_CronController::schedule() function. But this code is not reached when the wp-cron.php file executes the cron job.

Due to this, the wp_reschedule_event() function will try to reschedule it, but because the ‘twice_weekly’ schedule isn’t initialized, it will fall back to rescheduling the event to be executed initially.

On my solution, this gave a 2-300 ms overhead on every single request.

The fix would be to ensure the ‘cron_schedules’ hook is also called for cron requests.

My workaround was to add the following lines to my functions.php file:

//
// WORKAROUND: The BackWpUp plugin doesn't reschedule events correctly
// This hook fixes a problem where each request would call the WP cron and perform a remote request
// The problem happened because the plugin doesn't initialize its cron schedule on the wp-cron.php page
//
if ( class_exists('Inpsyde_PhoneHome_CronController') ) {
  function fix_backwpup_cron_schedule( $schedules ) {

    is_array( $schedules ) or $schedules = array();
    $label = __( 'Every %d days', 'inpsyde-phone-home' );

    $interval = apply_filters( 'inpsyde-phone-home-cron-interval', Inpsyde_PhoneHome_CronController::RECURRENCE_INTERVAL );
    is_int( $interval ) or $interval = Inpsyde_PhoneHome_CronController::RECURRENCE_INTERVAL;

    $schedules[ Inpsyde_PhoneHome_CronController::RECURRENCE_KEY ] = array(
      'interval' => $interval,
      'display'  => sprintf( $label, ceil( $interval / DAY_IN_SECONDS ) )
    );

    return $schedules;
  }
  add_filter( 'cron_schedules', 'fix_backwpup_cron_schedule' );
}