Fatal error: Uncaught Error: Class 'Zend\ServiceManager\AbstractPluginManager' not found in /home/app/htdocs/ninja/vendor/zendframework/zend-validator/src/ValidatorPluginManager.php:18 Stack trace: #0 {main} thrown in /home/app/htdocs/ninja/vendor/zendframework/zend-validator/src/ValidatorPluginManager.php on line 18