Fatal error: Uncaught Error: Class "Magento\Framework\Model\ResourceModel\Db\AbstractDb" not found in /home/airtimer/public_html/vendor/magento/module-theme/Model/ResourceModel/Design.php:14 Stack trace: #0 {main} thrown in /home/airtimer/public_html/vendor/magento/module-theme/Model/ResourceModel/Design.php on line 14