xss_clean and moveing from 2.2 to 3.0

Hello,


I just moved our app from ci 2.2 to 3.0 and we getting errors with forms (registration, login, email/password remainder ), where xss_clean is added to validation, for example:
$this->form_validation->set_rules('email','email','trim|required|valid_email|xss_clean');
the following error is generated on the every form on submit:
"Unable to access an error message corresponding to your field name"
(Probably something easy and obvious but not sure why is this happening, checked upgrading from a previous version and probably i missed something)

regards
mm