for a temporary workaround in case you updated without backing up! LOL
try linking directly to /wp-includes/pluggable.php in /wp-content/mu-plugins/PluginOrganizerMU.class.php
ie at line 11 change the following from:
License: GPL2
*/
to:
License: GPL2
*/
require_once(ABSPATH . ‘wp-includes/pluggable.php’);
works for me at least until OD can update this awesome plugin!
HTH