on running admin/cron.php , error with message_send() call while processing assignment_cron()

Processing assignment submission 109

Notice: Undefined property: stdClass::$component in /home/aparup/mcode/m20/mysql/moodle/lib/messagelib.php on line 114

Call Stack:
0.0003 636048 1.

{main}() /home/aparup/mcode/m20/mysql/moodle/admin/cron.php:0
0.2393 23221536 2. cron_run() /home/aparup/mcode/m20/mysql/moodle/admin/cron.php:79
0.5194 42633280 3. assignment_cron() /home/aparup/mcode/m20/mysql/moodle/lib/cronlib.php:87
0.5957 46764080 4. message_send() /home/aparup/mcode/m20/mysql/moodle/mod/assignment/lib.php:2621


Notice: Undefined property: stdClass::$name in /home/aparup/mcode/m20/mysql/moodle/lib/messagelib.php on line 114

Call Stack:
0.0003 636048 1. {main}

() /home/aparup/mcode/m20/mysql/moodle/admin/cron.php:0
0.2393 23221536 2. cron_run() /home/aparup/mcode/m20/mysql/moodle/admin/cron.php:79
0.5194 42633280 3. assignment_cron() /home/aparup/mcode/m20/mysql/moodle/lib/cronlib.php:87
0.5957 46764080 4. message_send() /home/aparup/mcode/m20/mysql/moodle/mod/assignment/lib.php:2621

!!! Coding error detected, it must be fixed by a programmer: Could not load preference message_provider___loggedoff. Does the component and name you supplied to message_send() match a row in message_providers? Message providers must appear in the database so users can configure how they will be notified when they receive messages. !!!
!! blah !!
!! Stack trace: * line 126 of /lib/messagelib.php: coding_exception thrown

• line 2621 of /mod/assignment/lib.php: call to message_send()
• line 87 of /lib/cronlib.php: call to assignment_cron()
• line 79 of /admin/cron.php: call to cron_run()
  !!