Try this: WITH group1 AS (

    select 1 DataNumber, 1 Data_Sort
    union
    select 2 DataNumber, 2 Data_Sort
    union
    select 3 Data_Number, 3 Data_Sort
),
    group2 AS (

        SELECT

Any chance this is a busy OLTP table and you have WITH (NOLOCK) as part of the query?  Your symptoms would probably qualify...  SET NOCOUNT ON does nothing but turn...

Have you recently upgraded SQL Server versions?   Also, the error message is suggestive of a package version issue, as if the version of the package file is just too old. ...

How, exactly, were you planning to detect that the current page is the first one in a group?   I realize I am; for all practical purposes; repeating your question back...

Duplicate post

I have to wonder why these calculations are being done in the report.  Not enough detail here to know whether or not the alternative of doing them in the dataset's...

Have you considered copying that file elsewhere, and then performing a database restore?  Push comes to shove, you'll have the copy to go back to....

Your going to want to use GROUP BY in a CTE to group by the e-mail address, and select that along with the MAX(LAST_UPDATED_DT).   Then you can join the CTE...