Fatal error: Uncaught Error: Class "Magento\Theme\Controller\Adminhtml\Design\Config\Save" not found in /var/www/magento/html/generated/code/Magento/Theme/Controller/Adminhtml/Design/Config/Save/Interceptor.php:7 Stack trace: #0 {main} thrown in /var/www/magento/html/generated/code/Magento/Theme/Controller/Adminhtml/Design/Config/Save/Interceptor.php on line 7