Fatal error: Uncaught Error: Interface "League\CommonMark\Node\StringContainerInterface" not found in /opt/lampp/htdocs/forum/flarum/vendor/league/commonmark/src/Node/RawMarkupContainerInterface.php:19 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/forum/flarum/vendor/league/commonmark/src/Node/RawMarkupContainerInterface.php on line 19