PHP Warning: Failed opening '' for inclusion

My log entries include the following when users create a new node.

include_once() [<a href='function.include'>function.include</a>]: Failed opening '' for inclusion (include_path='.:/usr/share/pear:/usr/share/php') in /path-to-drupal/modules/job_queue/job_queue.module on line 62.

Please let me know how to fix this issue. Thank you.