Fatal error: Uncaught Error: Class "MediaWiki\Api\ApiBase" not found in C:\xampp\htdocs\extensions\DiscussionTools\includes\ApiDiscussionToolsPreview.php:18 Stack trace: #0 {main} thrown in C:\xampp\htdocs\extensions\DiscussionTools\includes\ApiDiscussionToolsPreview.php on line 18