Fatal error: Uncaught Error: Class "yii\validators\Validator" not found in /var/www/html/prod/vendor/mootensai/yii2-optimistic-lock-validator/OptimisticLockValidator.php:8 Stack trace: #0 {main} thrown in /var/www/html/prod/vendor/mootensai/yii2-optimistic-lock-validator/OptimisticLockValidator.php on line 8