Describe the bug
Adding a count() to either the select or having clause of a GROUP BY performed against a sub-selected query generates:

Msg 0, Level 20, State 1, Line 8
Object reference not set to an instance of an object.

To Reproduce
Query to reproduce the behavior:

I can execute this query without the having count(*) > 1 clause, but it fails with the error above when I add that clause. I've also tried count(distinct t.owk_workrequesttype) but get the same error.

select t.owk_wrno
from 
(
select distinct owk_wrno,owk_workrequesttype
from owk_workrequest wr
where owk_wrno is not null
) t
group by t.owk_wrno
having count(*) > 1
;

Same error occurs using this query:

select t.owk_wrno,count(distinct t.owk_workrequesttype) as [count]
from 
(
select distinct owk_wrno,owk_workrequesttype
from owk_workrequest wr
where owk_wrno is not null
) t
group by t.owk_wrno

Expected behavior
Query should list owk_wrno values that have more than one owk_workrequesttype in the owk_workrequest table.

Screenshots

Environment (please complete the following information):

• SQL 4 CDS edition: XrmToolbox
• Results of SELECT @@VERSION:
  Microsoft Dataverse - 9.2.25061.154
  SQL 4 CDS - 9.6.1.0
  May 02 2025 14:00:23
  Copyright © 2020 - 2025 Mark Carrington

Additional context
n/a

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