Sample error 1[Wed Jan 10 14:56:38.031846 2018] [:error] [pid 9378] [client 115.85.11.98:23443] PHP Fatal error: Class 'DOMDocument' not found in /var/www/sites/site.example.com/docroot/core/lib/Drupal/Component/Utility/Html.php on line 286 Solution: 1apt-get install php5.6-dom See details in …