Fatal error: Uncaught Error: Interface "MediaWiki\Installer\Hook\LoadExtensionSchemaUpdatesHook" not found in /usr/www/otte/public/sphunt1/extensions/DiscussionTools/includes/Hooks/InstallerHooks.php:15 Stack trace: #0 {main} thrown in /usr/www/otte/public/sphunt1/extensions/DiscussionTools/includes/Hooks/InstallerHooks.php on line 15