Fatal error: Uncaught Error: Class 'yii\db\Migration' not found in /var/www/html/autocar/migrations/m200831_145727_add_email_callback_tbl2.php:8 Stack trace: #0 {main} thrown in /var/www/html/autocar/migrations/m200831_145727_add_email_callback_tbl2.php on line 8