Catchable fatal error on checkout page

#1

Hi,
we are using s2member together with a commercial template called LMS by DesignThemes which integrates and works with s2Member, here is the documentation of the template: http://wedesignthemes.com/themes/lms/docs/#dt_defaultcourses .
Now there is a new error in the checkout page, which says: Catchable fatal error: Object of class WP_Post could not be converted to string in /home/daytra47/public_html/wp-content/plugins/s2member/src/includes/classes/utils-strings.inc.php on line 235
We tried to make the downgrade to the previous version of February, but this didn’t solve the problem!
We didn’t change anything to the website code, what could cause this issue?
We are using the latest version of Wordpress Network and few days ago everything was working well…
Any help will be appreciated

#2

Have you switched to a default WordPress theme to see if the error disappears? Just because a theme developer says they support s2Member doesn’t make it so. In fact, I would say that anything they’ve done to “work with s2Member” increases the chance of something breaking when either the theme or s2Member is updated.