ATTENTION, latest mailchimp plugin update causes fatal error:
"Fatal error: Class 'WPMUDEV_MailChimp_Form' not found in /home/wordpress/public_html/wp-content/plugins/mailchimp-sync/front/widget.php on line 38"
And will halt all sites on multi-site network.
Please review and make aware to everybody that has this plugin running.
Way to resolve immediately, remove the mailchimp sync plugin located in: /wp-config/plugins/mailchimp-sync