Fatal error: Uncaught Error: Class 'Magento\Catalog\Ui\DataProvider\Product\Form\Modifier\AbstractModifier' not found in /home/esecureh/public_html/magdemo/vendor/magento/module-downloadable/Ui/DataProvider/Product/Form/Modifier/Links.php:26 Stack trace: #0 {main} thrown in /home/esecureh/public_html/magdemo/vendor/magento/module-downloadable/Ui/DataProvider/Product/Form/Modifier/Links.php on line 26