Install Odoo 9 – CentOS 7
I've found that if you insist on installing Odoo on CentOS, like I do, doing…
The solution two this error is one of two things, either session create is not checking for an existing session before starting one, or the php.ini has session.auto_start enabled.
Make sure you create a session by checking if one doesn’t already exist:
If you are sure this has been set properly then the following could be the solution:
Restart apache / php-fpm and see whether this solves your problem