Rookie mistake with join - sql-server

Question

I believe I have made a rookie mistake with the last join but I cannot see what it is. The code worked until I needed to add the last entry recorded in the DONCOMMS table. (This table contains all the communications for each donor) Now I get 3 duplicate lines for every entry from the first table.
The original report shows me all the donor pledges from DON0010 and links the area description and donor from the tables AREA and DON0001 respectively. I now want to bring out the latest communication found in DONCOMMS for each pledge found in DON0010.
select
pl.[PLEDGE_NO]
,d1.[DONOR_NO]
,rtrim(pl.DONOR) DONOR
,d1.[CONTACT_NAME]
,d1.[AREA1]
,a1.[DESCRIPTION]
,pl.[AMOUNT]
,pl.[AMOUNT_RECVD]
,pl.[TYPE]
,ISNULL(t2.[COMM_TYPE],'') AS COMM_TYPE
,ISNULL(t2.[REFERENCE],'') AS REFERENCE
,ISNULL(t2.[DETAIL],'') AS DETAIL
,replace(isnull(convert(varchar, t2.[DATE], 103),''),'01/01/1753','') COMMS_DATE
,ISNULL(t2.[CONTACT],'') AS CONTACT
from don0010 pl
left join DON0001 d1 on pl.[DONOR] = d1.[DONOR]
left join AREA1 a1 on d1.[AREA1] = a1.[AREA]
**left join (Select * from doncomms dc where dc.DATE = (SELECT MAX(DATE) FROM doncomms WHERE DONOR_NO = dc.DONOR_NO) and ENTITY = 'C') t2
on t2.[DONOR_NO] = d1.[DONOR_NO]**

Answer 1

select
pl.[PLEDGE_NO]
,d1.[DONOR_NO]
,rtrim(pl.DONOR) DONOR
,d1.[CONTACT_NAME]
,d1.[AREA1]
,a1.[DESCRIPTION]
,pl.[AMOUNT]
,pl.[AMOUNT_RECVD]
,pl.[TYPE]
,ISNULL(t2.[COMM_TYPE],'') AS COMM_TYPE
,ISNULL(t2.[REFERENCE],'') AS REFERENCE
,ISNULL(t2.[DETAIL],'') AS DETAIL
,replace(isnull(convert(varchar, t2.[DATE], 103),''),'01/01/1753','') COMMS_DATE
,ISNULL(t2.[CONTACT],'') AS CONTACT
from don0010 pl
left join DON0001 d1 on pl.[DONOR] = d1.[DONOR]
left join AREA1 a1 on d1.[AREA1] = a1.[AREA]
outer apply
(
select top 1 with ties dc.*
from doncomms dc
where dc.DONOR_NO = d1.DONOR_NO and dc.ENTITY = 'C'
order by dc.DATE desc
) t2

Answer 2

The problem usually is you have several rows with DATE = MAX(DATE)
Try this query alone to find out if same DONOR_NO appear more than once
Select DONOR_NO, count(*)
from doncomms dc
where dc.DATE = (SELECT MAX(DATE)
FROM doncomms
WHERE DONOR_NO = dc.DONOR_NO)
and ENTITY = 'C'
GROUP BY DONOR_NO
In that case is better if you use a CTE syntaxis and ROW_NUMBER()
WITH cte as (
SELECT *
FROM (
SELECT *,
ROW_NUMBER() OVER(PARTITION BY DONOR_NO ORDER BY DATE DESC) as rn
FROM doncomms
WHERE ENTITY = 'C'
) T
WHERE T.rn = 1
)
select *
from don0010 pl
left join DON0001 d1 on pl.[DONOR] = d1.[DONOR]
left join AREA1 a1 on d1.[AREA1] = a1.[AREA]
left join cte as t2
on t2.[DONOR_NO] = d1.[DONOR_NO]

Answer 3

Thank you Juan, I just needed to add the field names to run as a view.
WITH cte as (
SELECT *
FROM (
SELECT *,
ROW_NUMBER() OVER(PARTITION BY DONOR_NO ORDER BY DATE DESC) as rn
FROM doncomms
WHERE ENTITY = 'C'
) T
WHERE T.rn = 1
)
select pl.[PLEDGE_NO]
,d1.[DONOR_NO]
,rtrim(pl.DONOR) DONOR
,d1.[CONTACT_NAME]
,d1.[AREA1]
,a1.[DESCRIPTION]
,pl.[AMOUNT]
,pl.[AMOUNT_RECVD]
,pl.[TYPE]
,pl.[SOURCE]
,d1.[POST_CODE] as DONOR_POSTCODE
,replace(isnull(convert(varchar, pl.PLEDGE_DATE, 103),''),'01/01/1753','') PLEDGE_DATE
,replace(isnull(convert(varchar, pl.[EVENT_DATE], 103),''),'01/01/1753','') EVENT_DATE
,rtrim(pl.DESCRIPTION1) DESCRIPTION1
,rtrim(pl.DESCRIPTION2) DESCRIPTION2
,pl.[COMPLETE]
,pl.[APPLICATION]
,rtrim(pl.COMMENT1) COMMENT1
,rtrim(pl.COMMENT2) COMMENT2
,pl.[MEMO]
,ISNULL(t2.[ENTERED_BY] , '') AS ENTERED_BY
,ISNULL(t2.[COMM_TYPE],'') AS COMM_TYPE
,ISNULL(t2.[REFERENCE],'') AS REFERENCE
,ISNULL(t2.[DETAIL],'') AS DETAIL
,replace(isnull(convert(varchar, t2.[DATE], 103),''),'01/01/1753','') COMMS_DATE
,ISNULL(t2.[CONTACT],'') AS CONTACT
from don0010 pl
left join DON0001 d1 on pl.[DONOR] = d1.[DONOR]
left join AREA1 a1 on d1.[AREA1] = a1.[AREA]
left join cte as t2
on t2.[DONOR_NO] = d1.[DONOR_NO]