Fatal error: Uncaught Error: Class 'craft\db\Migration' not found in /home/mpolsk5/public_html/visibilityfuel.com/vendor/craftcms/cms/src/migrations/m150428_231346_userpreferences.php:16 Stack trace: #0 {main} thrown in /home/mpolsk5/public_html/visibilityfuel.com/vendor/craftcms/cms/src/migrations/m150428_231346_userpreferences.php on line 16