Fatal error: Uncaught Error: Class "Whoops\Handler\Handler" not found in /srv/www/sites/public/starter-cms/vendor/filp/whoops/src/Whoops/Handler/XmlResponseHandler.php:17 Stack trace: #0 {main} thrown in /srv/www/sites/public/starter-cms/vendor/filp/whoops/src/Whoops/Handler/XmlResponseHandler.php on line 17