Fatal error: Uncaught Error: Class "core_external\external_api" not found in C:\Apache24\htdocs\moodle\question\bank\columnsortorder\classes\external\set_hidden_columns.php:34 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\moodle\question\bank\columnsortorder\classes\external\set_hidden_columns.php on line 34