Fatal error: Uncaught Error: Class "OpenSpout\Writer\Exception\WriterException" not found in /srv/www/htdocs/moodle/lib/openspout/src/Writer/Exception/InvalidSheetNameException.php:7 Stack trace: #0 {main} thrown in /srv/www/htdocs/moodle/lib/openspout/src/Writer/Exception/InvalidSheetNameException.php on line 7