>>>>Maybe ALL Date_Clos field are NULLs?
>>>
>>>I double checked and all but one of the selected records have valid DATE_CLOS. That is, many have NULL and one has a valid date.
>>>Should I eliminate the NULL dates from the SQL Select?
>>
>>Yes, from the sub-select NULL is I don't know, so it might be the largest, the lowest, 'cause I don't know.
>
>Adding IS NOT NULL does not help. Still no records selected. Aliases do not help either.

What is the return of the subselect, running alone? Something meaningful?
Please full code, I have no idea where you added IS NOT NULL