Fatal error: Uncaught Error: Class "core_external\external_api" not found in C:\xampp\htdocs\moodle\question\bank\managecategories\classes\external\move_category.php:38 Stack trace: #0 {main} thrown in C:\xampp\htdocs\moodle\question\bank\managecategories\classes\external\move_category.php on line 38