Fatal error: Call to a member function toArray() on a non-object in /var/www/voltrad.de/application/modules/produkte/models/ManufacturerMapper.php on line 17

Call Stack:
    0.0002     657344   1. {main}() /var/www/voltrad.de/public/index.php:0
    0.2374   15604008   2. Zend_Application->run() /var/www/voltrad.de/public/index.php:19
    0.2374   15604008   3. Zend_Application_Bootstrap_Bootstrap->run() /var/www/voltrad.de/library/Zend/Application.php:366
    0.2375   15604144   4. Zend_Controller_Front->dispatch() /var/www/voltrad.de/library/Zend/Application/Bootstrap/Bootstrap.php:97
    0.2843   18425416   5. Zend_Controller_Dispatcher_Standard->dispatch() /var/www/voltrad.de/library/Zend/Controller/Front.php:954
    0.2895   18897832   6. Zend_Controller_Action->dispatch() /var/www/voltrad.de/library/Zend/Controller/Dispatcher/Standard.php:295
    0.2895   18905976   7. Produkte_HerstellerController->listeAction() /var/www/voltrad.de/library/Zend/Controller/Action.php:516
    0.2904   18976704   8. mehrWEB\Mapper\MapperAbstract->retrieveByPK() /var/www/voltrad.de/application/modules/produkte/controllers/HerstellerController.php:7
    0.2904   18976784   9. Produkte_Model_ManufacturerMapper->_fetchById() /var/www/voltrad.de/library/mehrWEB/Mapper/MapperAbstract.php:67