Invalid controller specified (robots.txt)

#0 /usr/local/www/apache22/data/www.medam.org.tr/library/Zend/Controller/Front.php(934): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#1 /usr/local/www/apache22/data/www.medam.org.tr/public/index.php(44): Zend_Controller_Front->dispatch()
#2 {main}