Fatal error: Uncaught Error: Interface "MediaWiki\Json\JsonUnserializable" not found in /var/www/html/extensions/SemanticMediaWiki/src/DataModel/SubSemanticData.php:25 Stack trace: #0 {main} thrown in /var/www/html/extensions/SemanticMediaWiki/src/DataModel/SubSemanticData.php on line 25