Fatal error: Uncaught Error: Class "Magento\Framework\Data\Form\Element\Fieldset" not found in /var/www/magento/html/generated/code/Magento/Framework/Data/Form/Element/Fieldset/Interceptor.php:7 Stack trace: #0 {main} thrown in /var/www/magento/html/generated/code/Magento/Framework/Data/Form/Element/Fieldset/Interceptor.php on line 7