Site unresponsive showing error message

I have transferred my domain and site to a new server (vps) following the same procedures as i have done with many other transfers ie database, back-ups all using ftp etc but with this site i am receiving an error message. Upon further inspection having checked the logs status it shows an error/warning message as follows;

AH01071: Got error ‘PHP message: PHP Warning: is_file(): open_basedir restriction in effect. File(/etc/wordpress/config.ini) is not within the allowed path(s): (/var/www/vhosts/virtual-tours-uk.co.uk/:/tmp/) in /var/www/vhosts/virtual-tours-uk.co.uk/httpdocs/PROD/wp-content/plugins/1and1-wordpress-assistant/inc/config.php on line 213’

What does this mean and how can i fix it. My server provider have informed that this is a wordpress issue and they cannot help.

Thank you in advance

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