Index: moodle/admin/user/user_bulk_message.php
--- moodle/admin/user/user_bulk_message.php Base (1.15)
+++ moodle/admin/user/user_bulk_message.php Locally Modified (Based On 1.15)
@@ -50,7 +50,7 @@
     $options->newlines = true;
     $options->smiley   = false;
 
-    $msg = format_text($formdata->messagebody, $formdata->format, $options);
+    $msg = format_text($formdata->messagebody['text'], $formdata->messagebody['format'], $options);
 
     list($in, $params) = $DB->get_in_or_equal($SESSION->bulk_users);
     $userlist = $DB->get_records_select_menu('user', "id $in", $params, 'fullname', 'id,'.$DB->sql_fullname().' AS fullname');

Index: moodle/admin/user/user_message_form.php
--- moodle/admin/user/user_message_form.php Base (1.5)
+++ moodle/admin/user/user_message_form.php Locally Modified (Based On 1.5)
@@ -9,10 +9,9 @@
         $mform->addElement('header', 'general', get_string('message', 'message'));
 
 
-        $mform->addElement('textarea', 'messagebody', get_string('messagebody'), array('rows'=>15, 'cols'=>60));
-        $mform->addRule('messagebody', '', 'required', null, 'client');
+        $mform->addElement('editor', 'messagebody', get_string('messagebody'), null, null);
+        $mform->addRule('messagebody', '', 'required', null, 'server');
         $mform->setHelpButton('messagebody', array('writing', 'reading', 'questions', 'richtext2'), false, 'editorhelpbutton');
-        $mform->addElement('format', 'format', get_string('format'));
 
         $this->add_action_buttons();
     }