Error on cron run

I first suspected that this issue https://www.drupal.org/project/commerce_ticketing/issues/3192100 → is still the cause for this error. I put some logger code into the the Class TicketReceiptMail.php and the output shows me ticket numbers which are not present anymore. The orders have been deleted already

      /* @var $order \Drupal\commerce_order\Entity\Order*/
      if ($order = $ticket->getOrder()) {
        \Drupal::logger('commerce_ticketing')->info('Order id no' .$order->id(). ' could be loaded. Underlying Ticket No: '. $ticket->getTicketNumber());
      } else {
        \Drupal::logger('commerce_ticketing')->error('Order class could not be loaded. ' . 'Ticket Id: ' .$ticket->id() . ' Ticket-No: ' .$ticket->getTicketNumber());
      }

It was caused by the fact that I exported my local dev database to production and there has been some leftovers in the queue-table. I truncated this table and the error is gone for now.

I was seeing the same error. Clearing the queue table as suggested in #2 seems to have fixed the problem.