I received the same error today on a fresh install of WordPress 3.5.2:
Fatal error: Call to a member function execute_backup() on a non-object in /home/mydomain/public_html/perm/wp-content/plugins/better-wp-security/inc/admin/process.php on line 113
Uninstalling Better WP Security plugin doesn’t seem to make sense as a solution since this plugin is what is being used to create the backup!
Developer?
