I got no results when I run the query :

SELECT aq.display_name, lqasc.ag_num, lqasc.timeofupdate AS tou, lqasc.is_loggedin_in_queue AS ili FROM queue_view as aq
RIGHT JOIN
(
 WITH cte AS
 (
   SELECT a.q_num, a.ag_num, a.timeofupdate, a.is_loggedin_in_queue,
         ROW_NUMBER() OVER (PARTITION BY q_num, ag_num ORDER BY timeofupdate DESC) AS rn
   FROM callcent_ag_queuestatus a
 )
 SELECT *
 FROM cte
 WHERE rn = 1
) AS lqasc
ON aq.dn = lqasc.q_num
WHERE aq.dn<>'850' AND aq.dn<>'815'


So I started breaking down the parts put just:

WITH cte AS
(
   SELECT a.q_num, a.ag_num, a.timeofupdate, a.is_loggedin_in_queue,
         ROW_NUMBER() OVER (PARTITION BY q_num, ag_num ORDER BY timeofupdate DESC) AS rn
   FROM callcent_ag_queuestatus a
)
SELECT *
FROM cte
WHERE rn = 1

And that resulted in an error message pop up saying

WITH not implemented.

I need this query to work.  I have read only access to the database server, so I cannot create a view.

This is using POSTGRESQL.