Fatal error: Uncaught Error: Interface 'Magento\CatalogInventory\Observer\ParentItemProcessorInterface' not found in /home/esecureh/public_html/magdemo/vendor/magento/module-configurable-product/Model/Inventory/ParentItemProcessor.php:21 Stack trace: #0 {main} thrown in /home/esecureh/public_html/magdemo/vendor/magento/module-configurable-product/Model/Inventory/ParentItemProcessor.php on line 21