Fatal error: Uncaught Error: Interface 'Magento\Framework\EntityManager\Operation\ExtensionInterface' not found in /home/esecureh/public_html/magdemo/vendor/magento/module-configurable-product/Model/Product/SaveHandler.php:19 Stack trace: #0 {main} thrown in /home/esecureh/public_html/magdemo/vendor/magento/module-configurable-product/Model/Product/SaveHandler.php on line 19