Fatal error: Uncaught Error: Interface "MediaWiki\Extension\DiscussionTools\ThreadItem\ThreadItem" not found in C:\xampp\htdocs\extensions\DiscussionTools\includes\ThreadItem\HeadingItem.php:5 Stack trace: #0 {main} thrown in C:\xampp\htdocs\extensions\DiscussionTools\includes\ThreadItem\HeadingItem.php on line 5