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