Invalid callback: Model for core/email_queue::send does not exist

[philow3n]

I'm experiencing an issue where store emails are not sending and when I check the schedule, all jobs marked email_queue::send are failing.

I also can't open and save the job 'core_email_queue_send_all' as it errors with output:

'Invalid callback: Model for core/email_queue::send does not exist'

In the message against the failure:

exception 'Mage_Core_Exception' with message 'Invalid callback: Model for core/email_queue::send does not exist' in /var/sites/t/mydomain.com/public_html/app/Mage.php:595 Stack trace: #0 /var/sites/t/mydomain.com/public_html/app/code/community/Aoe/Scheduler/Helper/Data.php(298): Mage::throwException('Invalid callbac...') ...

The file exists at /app/code/core/Mage/Core/Model/Email/Queue.php so really not sure why no emails are being sent from the store - no core files have ever been touched.

Any ideas would be appreciated.

[lamskoy]

What happens if you call in code: Mage::getModel('core/email_queue')->send() ?