eXtplorer - PHP-based File Manager

When I access webdav.php, got error below.

PHP Fatal error: Call to undefined function activate_user() in /path/to/eXtplorer_ 2.1.0-RC3/webdav_authenticate.php on line 70

eXtplorer 2.1.0-RC3:
% find . | xargs egrep -n 'function +activate_user'
%

eXtplorer 2.0.1:
% find . | xargs egrep -n 'function +activate_user'
./include/users.php:82:function activate_user($user,$pass) {
%

function activate_user() was deleted?
Is it bug?