Fatal error: Uncaught Error: Class 'yii\base\Behavior' not found in /var/www/html/autocar/vendor/creocoder/yii2-nested-sets/src/NestedSetsBehavior.php:23 Stack trace: #0 {main} thrown in /var/www/html/autocar/vendor/creocoder/yii2-nested-sets/src/NestedSetsBehavior.php on line 23