How disable csrf token of osclass system?

[AdrianOlmedo]

Each time the token period expires and the form is sent, show "CSRF Token invalid".
Why not automatically generates a new one?

[_CONEJO]

Because the token protects you against CSRF attacks. It's based on the session time, so if the token is expired, your session should be too.
You could try putting a higher value for your session lifetime ( http://php.net/manual/en/session.configuration.php#ini.session.gc-maxlifetime ) this is on your php.ini configuration