Invalid argument in Forms.php

Hi
i’ve upgrated wp-members to the latest version (2.9.0) but now i got this error
Warning: Invalid argument supplied for foreach() in /web/htdocs/www.assocontroller.it/home/WordPress/wp-content/plugins/wp-members/forms.php on line 318 Warning: Invalid argument supplied for foreach() in /web/htdocs/www.assocontroller.it/home/WordPress/wp-content/plugins/wp-members/forms.php on line 349
instead of the login form (http://www.assocontroller.it/login/)

how could i solve it?
let me know if you need further details to make your understanding of the problem easier
thanks
mauro

https://wordpress.org/plugins/wp-members/