Fatal error: Uncaught Error: Class "Magento\Backend\Block\Template" not found in /var/www/magento/html/app/code/MagicToolbox/MagicZoomPlus/Block/Adminhtml/Settings/Edit/Tab/Promo.php:9 Stack trace: #0 {main} thrown in /var/www/magento/html/app/code/MagicToolbox/MagicZoomPlus/Block/Adminhtml/Settings/Edit/Tab/Promo.php on line 9