Fatal error: Uncaught Error: Class "yii\bootstrap\Widget" not found in /var/www/html/web/yii/basic/vendor/yiisoft/yii2-bootstrap/src/ButtonGroup.php:44 Stack trace: #0 {main} thrown in /var/www/html/web/yii/basic/vendor/yiisoft/yii2-bootstrap/src/ButtonGroup.php on line 44