Fatal error: Uncaught Error: Class 'yii\helpers\StringHelper' not found in /var/www/html/ng-crm/yiiapp/vendor/johnitvn/yii2-ajaxcrud/src/generators/default/search.php:12 Stack trace: #0 {main} thrown in /var/www/html/ng-crm/yiiapp/vendor/johnitvn/yii2-ajaxcrud/src/generators/default/search.php on line 12