A Joomla website displays the blank screen. However with '
display_errors = On' in PHP configuration, the following error could be observed:
mod_fcgid: stderr: PHP Fatal error: Class 'DateTime' not found in /var/www/vhosts/domain.tld/httpdocs/libraries/joomla/utilities/date.php online 20
PHP < 5.2 is installed on the server.
Jooma requires PHP 5.2 in order to run correctly. With old PHP version it fails to load some functions that were introduced in 5.2.
/usr/local/psa/admin/bin/autoinstaller' and install a proper version of PHP.