CTEs need to be at the very beginning of the statement, because of the way
the "WITH" keyword has been overloaded.

So, just make sure you have a semi-colon at the end of the preceding
statement.  e.g. instead of:

SET NOCOUNT ON

WITH cte AS
(
   ...

Use:

SET NOCOUNT ON;

WITH cte AS
(
   ...

I have seen some use the following convention, but I am not particularly
fond of it (I have no objective evidence to back that up, either):

;WITH cte AS
(
   ...

The FROM in the outer SELECT is missing.

with cte
as
(
select
  AddressID, PersonID, DateAdded,
  row_number() over(partition by AddressID order by PersonID DESC) as
rn
from
  dbo.Person
)
select * FROM cte
where rn > 1;

Roy Harvey
Beacon Falls, CT