Fatal error: Uncaught Error: Interface "Flarum\Extend\ExtenderInterface" not found in /opt/lampp/htdocs/forum/flarum/vendor/fof/extend/src/Extend/OAuthController.php:20 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/forum/flarum/vendor/fof/extend/src/Extend/OAuthController.php on line 20