Updating to latest version of Membership has crashed my site


I just attempted to install an updated version of Membership to my site (via FTP, overwriting the old version of Membership). My site is now inaccessible.

This is the error message that was generated:

PHP Fatal error: Cannot redeclare m_cache_favourite_actions() in /nas/wp/www/cluster-1430/smith/wp-content/plugins/membership/membershipincludes/addons/default.admin.rules.php on line 513

Any help you could provide would be appreciated.