Fatal error: Uncaught Error: Class 'XMLWriter' not found in /var/www/horaro/src/horaro/Library/ScheduleTransformer/XmlTransformer.php:35 Stack trace: #0 /var/www/horaro/src/horaro/WebApp/Controller/FrontendController.php(83): horaro\Library\ScheduleTransformer\XmlTransformer->transform(Object(horaro\Library\Entity\Schedule), true, true) #1 [internal function]: horaro\WebApp\Controller\FrontendController->scheduleExportAction(Object(Symfony\Component\HttpFoundation\Request)) #2 /var/www/horaro/vendor/symfony/http-kernel/HttpKernel.php(153): call_user_func_array(Array, Array) #3 /var/www/horaro/vendor/symfony/http-kernel/HttpKernel.php(68): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1) #4 /var/www/horaro/vendor/silex/silex/src/Silex/Application.php(496): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #5 /var/www/horaro/vendor/silex/silex/src/Silex/Application.php(477): Silex\Application->handle(Object(Symfon in /var/www/horaro/src/horaro/Library/ScheduleTransformer/XmlTransformer.php on line 35