Fatal error: Uncaught Error: Class "yii\db\Migration" not found in /var/www/html/_old/vendor/azbuco/yii2-user/migrations/m181028_083114_create_user_table.php:10 Stack trace: #0 {main} thrown in /var/www/html/_old/vendor/azbuco/yii2-user/migrations/m181028_083114_create_user_table.php on line 10