I updated AddThis for Wordpress 4.0.7 to AddThis Sharing Buttons 5.0.7 and scheduled emails stopped sending. I determined that the cron job was getting a fatal error.
Job path - "https://www.xxxxxx.org/wordpress/wp-content/plugins/civicrm/civicrm/bin/cron.php
Fatal error: Call to a member function getConfigs() on a non-object in /home/xxxxxx/public_html/wordpress/wp-content/plugins/addthis/addthis_addjs_new.php on line 57
Here is a snip from the file that caused the error:
// We haven't added our JS yet. Or at least better not have.
$this->_js_added = false;
LINE 57: $this->_options = $addThisConfigs->getConfigs();
// Version of AddThis code to use
$this->atversion = $this->_options['atversion'];
The cron job was referencing a file in our AddThis plugin folder. It seems to me that file and plugin should have nothing to do with sending email from CiviCRM. I am not well versed in how cron jobs work, so any information you can provide would be appreciated. The day that this plugin was updated to the latest version 5.0.7, which included the file shown in the fatal error above, is the day scheduled jobs stopped sending and the cron job started erroring out. I deleted the updated plugin and reinstalled 4.0.7, the known good version, which did not contain that file. Scheduled emails now send.