Fatal error: Uncaught Error: Class "yii\base\Behavior" not found in /home/leasingm/public_html/public_html/vendor/creocoder/yii2-nested-sets/src/NestedSetsBehavior.php:23 Stack trace: #0 {main} thrown in /home/leasingm/public_html/public_html/vendor/creocoder/yii2-nested-sets/src/NestedSetsBehavior.php on line 23