Membership filter by status warning

Hi there,
When trying to filter members by status in the membership plugin, we get the following error:

Warning: Missing argument 2 for wpdb::prepare(), called in /home/USER/public_html/wp-content/plugins/membership/membershipincludes/classes/class.membersearch.php on line 142 and defined in /home/USER/public_html/wp-includes/wp-db.php on line 992

It seems to filter still, but this warning is just above the edit members page title every time.