Fatal error: Uncaught Error: Class "craft\db\Migration" not found in /home/leasingm/public_html/public_html/vendor/craftcms/cms/src/migrations/m170206_142126_system_name.php:12 Stack trace: #0 {main} thrown in /home/leasingm/public_html/public_html/vendor/craftcms/cms/src/migrations/m170206_142126_system_name.php on line 12