Fatal error: Uncaught Error: Interface "Flarum\Extend\ExtenderInterface" not found in /opt/lampp/htdocs/forum/flarum/vendor/fof/extend/src/Extend/ExtensionSettings.php:21 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/forum/flarum/vendor/fof/extend/src/Extend/ExtensionSettings.php on line 21