Fatal error: Uncaught Error: Class 'kartik\base\Widget' not found in /var/www/html/autocar/vendor/kartik-v/yii2-tree-manager/src/TreeView.php:31 Stack trace: #0 {main} thrown in /var/www/html/autocar/vendor/kartik-v/yii2-tree-manager/src/TreeView.php on line 31