Fatal error: Uncaught Error: Class 'DOMDocument' not found in /var/www/piwigo/include/emogrifier.class.php:406
Stack trace:
#0 /var/www/piwigo/include/emogrifier.class.php(233): Emogrifier->createXmlDocument()
#1 /var/www/piwigo/include/functions_mail.inc.php(955): Emogrifier->emogrify()
#2 /var/www/piwigo/include/functions_mail.inc.php(853): move_css_to_body('<!DOCTYPE html ...')
#3 /var/www/piwigo/include/functions_mail.inc.php(458): pwg_mail(Array, Array, Array)
#4 /var/www/piwigo/admin/include/updates.class.php(206): pwg_mail_admins(Array, Array, false, true)
#5 /var/www/piwigo/include/page_tail.php(48): updates->notify_piwigo_new_versions()
#6 /var/www/piwigo/tags.php(167): include('/var/www/piwigo...')
#7 {main}
thrown in /var/www/piwigo/include/emogrifier.class.php on line 406