Remove PHP’s open_basedir restriction in Plesk
If you have an open_basedir restriction that is causing issues with a domain, you can remove the restriction easily. First, put the following text in /home/httpd/vhosts/[domain]/conf/vhost.conf:
<Directory /home/httpd/vhosts/[domain]/httpdocs>
php_admin_value open_basedir none
</Directory>
If there was already a vhost.conf in the directory, then just reload Apache. Otherwise, run the magic wand:
/usr/local/psa/admin/bin/websrvmng -av
Then reload Apache:
/etc/init.d/httpd reload