Fatal error: Uncaught Error: Interface "League\CommonMark\Extension\ExtensionInterface" not found in /opt/lampp/htdocs/forum/flarum/vendor/league/commonmark/src/Extension/GithubFlavoredMarkdownExtension.php:23 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/forum/flarum/vendor/league/commonmark/src/Extension/GithubFlavoredMarkdownExtension.php on line 23