Fatal error: Uncaught Error: Class 'yii\helpers\StringHelper' not found in /var/www/html/ng-crm/yiiapp/vendor/johnitvn/yii2-ajaxcrud/src/generators/default/controller.php:13 Stack trace: #0 {main} thrown in /var/www/html/ng-crm/yiiapp/vendor/johnitvn/yii2-ajaxcrud/src/generators/default/controller.php on line 13