Fatal error: Uncaught Error: Class "HTMLPurifier_HTMLModule" not found in /srv/www/htdocs/moodle/lib/htmlpurifier/HTMLPurifier/HTMLModule/Iframe.php:10 Stack trace: #0 {main} thrown in /srv/www/htdocs/moodle/lib/htmlpurifier/HTMLPurifier/HTMLModule/Iframe.php on line 10