Fatal error: Uncaught Error: Class "Magento\Backend\Block\Widget\Form\Renderer\Fieldset\Element" not found in /var/www/magento/html/app/code/MagicToolbox/MagicZoomPlus/Block/Adminhtml/Settings/Edit/Form/Renderer/Fieldset/Element.php:8 Stack trace: #0 {main} thrown in /var/www/magento/html/app/code/MagicToolbox/MagicZoomPlus/Block/Adminhtml/Settings/Edit/Form/Renderer/Fieldset/Element.php on line 8