Error reading from Database after filter query for all Managers

Debug info: Unknown column 'a.timestart' in 'where clause'
SELECT id, username, email, firstname, lastname, city, country, lastaccess, confirmed, mnethostid
FROM mdl_user
WHERE deleted <> 1 AND id IN (SELECT userid
FROM mdl_role_assignments a
WHERE a.contextid=1 AND a.roleid=1 AND a.timestart<1292251076
AND (a.timeend=0 OR a.timeend>1292251076))
ORDER BY firstname ASC LIMIT 0, 30
[array (
)]
Stack trace:

• line 391 of /lib/dml/moodle_database.php: dml_read_exception thrown
• line 759 of /lib/dml/mysqli_native_moodle_database.php: call to moodle_database->query_end()
• line 296 of /lib/datalib.php: call to mysqli_native_moodle_database->get_records_sql()
• line 150 of /admin/user.php: call to get_users_listing()