When accessing a PHP-based website, a lot of the following warnings are shown on top of the website content or in domain log
CONFIG_TEXT: Warning: require() [function.require]: open_basedir restriction in effect. File(/var/lib/php5/c-sql_statement.php) is not within the allowed path(s): (/var/www/vhosts/example.com/:/tmp/) in /var/www/vhosts/example.com/httpdocs/script.php on line 101
open_basedir PHP directive for a website lacks paths which are accessed by a PHP script.
Add directories from warnings to the
open_basedir directive as described in the Resolution section of the article Domain does not work: open_basedir restriction in effect.