error open_basedir Plesk 10.4.4

[yasirr]

dear plesk team and members.i am new to plesk .look nice and stable.but i found this error any body helps me.
Thx
Regards

Warning: file_exists(): open_basedir restriction in effect. File(/var/www/vhosts/xxxxx/httpdocs/forum/cometchat/extensions/index.html/code.php) is not within the allowed path(s): (/var/www/vhosts/xxxx/httpdocs/:/tmp/) in /var/www/vhosts/xxx/httpdocs/forum/cometchat/admin/extensions.m.php on line 75