Error: Class 'DOMDocument' not found in Drupal\Component\Utility\Html::load() (line 286 of core/lib/Drupal/Component/Utility/Html.php)

Question

After a Debian update my Drupal 8 installation can not show single nodes and spits the following error.

Error: Class 'DOMDocument' not found in Drupal\Component\Utility\Html::load() (line 286 of core/lib/Drupal/Component/Utility/Html.php).

I have no clue what to do and have installed all required php extensions, following some other issues with the same error.

I already removed all suspicious contrib modules and I am lost now with a broken project.

Any suggestions would be very helpful.
ENV: Drupal 8.5 | PHP 7.2.9

Answer 1

That sound like it can't find php Dom extension, to get that try sudo apt-get install php-xml, it should solve your problem

Answer 2

Even after installing PHP-dom and PHP-XML, I was getting the same error. So I did a restart of PHP-fpm and Ngnix. It started working after that