Fatal error: Uncaught Error: Class "Magento\Config\Block\System\Config\Form\Fieldset" not found in /var/www/magento/html/app/code/Amasty/Rules/Block/Adminhtml/System/Config/Information.php:15
Stack trace:
#0 {main}
thrown in /var/www/magento/html/app/code/Amasty/Rules/Block/Adminhtml/System/Config/Information.php on line 15