zend error

Fatal error: Uncaught exception 'Zend\ServiceManager\Exception\InvalidArgumentException' with message '$initializer should be callable.' in /home/nf193195/public_html/rekrutacja/vendor/zendframework/zendframework/library/Zend/ServiceManager/ServiceManager.php:366 Stack trace: #0 /home/nf193195/public_html/rekrutacja/vendor/zendframework/zendframework/library/Zend/Mvc/Service/ServiceManagerConfig.php(142): Zend\ServiceManager\ServiceManager->addInitializer() #1 /home/nf193195/public_html/rekrutacja/vendor/zendframework/zendframework/library/Zend/ServiceManager/ServiceManager.php(128): Zend\Mvc\Service\ServiceManagerConfig->configureServiceManager(Object(Zend\ServiceManager\ServiceManager)) #2 /home/nf193195/public_html/rekrutacja/vendor/zendframework/zendframework/library/Zend/Mvc/Application.php(250): Zend\ServiceManager\ServiceManager->__construct(Object(Zend\Mvc\Service\ServiceManagerConfig)) #3 /home/nf193195/public_html/rekrutacja/public/index.php(17): Zend\Mvc\Application::init(Array) #4 {main} thrown in /home/nf193195/public_html/rekrutacja/vendor/zendframework/zendframework/library/Zend/ServiceManager/ServiceManager.php on line 366