Fatal error: Uncaught Error: Class "Zend_Feed_Pubsubhubbub_CallbackAbstract" not found in C:\SHC\xampp\htdocs\shc_mobile_backend\vendor\diablomedia\zendframework1\library\Zend\Feed\Pubsubhubbub\Subscriber\Callback.php:28
Stack trace:
#0 {main}
thrown in C:\SHC\xampp\htdocs\shc_mobile_backend\vendor\diablomedia\zendframework1\library\Zend\Feed\Pubsubhubbub\Subscriber\Callback.php on line 28