Fatal error: Uncaught Error: Class 'Magento\Backend\Block\Widget\Form\Generic' not found in /home/esecureh/public_html/magdemo/vendor/magento/module-configurable-product/Block/Adminhtml/Product/Edit/AttributeSet/Form.php:16 Stack trace: #0 {main} thrown in /home/esecureh/public_html/magdemo/vendor/magento/module-configurable-product/Block/Adminhtml/Product/Edit/AttributeSet/Form.php on line 16