Fatal error: Uncaught Error: Class "MediaWiki\SpecialPage\SpecialPage" not found in /home/hiphopdi/public_html/wiki2/extensions/CategoryTree/includes/CategoryTreePage.php:37 Stack trace: #0 {main} thrown in /home/hiphopdi/public_html/wiki2/extensions/CategoryTree/includes/CategoryTreePage.php on line 37