Fatal error: Uncaught Error: Class "Ramsey\Collection\AbstractCollection" not found in /opt/lampp/htdocs/forum/flarum/vendor/ramsey/collection/src/AbstractSet.php:25 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/forum/flarum/vendor/ramsey/collection/src/AbstractSet.php on line 25