An error has occurred

                Zend_Controller_Dispatcher_Exception: Invalid controller specified (a) in /home/inventory/commons/Zend/Controller/Dispatcher/Standard.php:248
Stack trace:
#0 /home/inventory/commons/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#1 /home/inventory/inventory/Software/htdocs/index.php(183): Zend_Controller_Front->dispatch()
#2 {main}