WD18 Queries, Subqueries, Problems... Help please

I can't find out what's wrong with below query.
It work ONLY in test mode with checked option:
"Run query without hQueryWithOutCorrection in test mode"
In app I get an error: "Aktivnost alias already used" (I do not use aliases)
Files are local HFSQLC/S. I checked every subquery one at time, and all worked as expected.

Does somebody have an idea?
Is it allowed to use subquery inside subquery?
(It work in some other cases)

SELECT 
	Clan.ClanID AS ClanID,	
	Oznaka.Oznaka AS Oznaka_Oz,	
	Clan.Broj AS Broj,	
	Clan.Prezime AS Prezime,	
	Clan.Ime AS Ime,	
	Titula.Naziv AS Naziv,
	Spol.Spol AS Spol,	
	Clan.Adresa AS Adresa,	
	Mjesto.PTT AS PTT,	
	Mjesto.NazivMjesta AS NazivMjesta,	
	Clan.StatusTip AS StatusTip,	
	Clan.StatusDatumOD AS StatusDatumOD,	
	Clan.StatusDatumDO AS StatusDatumDO,	
	AktivnostUpit.sum_Bodovi,	
	AktivnostUpit.sum_BodoviRegulativa,	
	AktivnostUpit.sum_BodoviOpcenito,
	StatusNaDan.StatusTip AS StatusTipAktualni,	
	StatusNaDan.Datum AS Datum
FROM 
	Clan
	LEFT OUTER JOIN Oznaka ON Clan.OznakaID = Oznaka.OznakaID
	LEFT OUTER JOIN Mjesto ON Clan.MjestoID = Mjesto.MjestoID	
	LEFT OUTER JOIN Titula ON Clan.TitulaID = Titula.TitulaID
	LEFT OUTER JOIN Spol   ON Clan.SpolID   = Spol.SpolID
	LEFT OUTER JOIN (
		SELECT 
		StatusNaDan.ClanID AS ClanID,	
		StatusNaDan.StatusTip AS StatusTip,	
		StatusNaDan.Datum AS Datum
		FROM 
		Status AS StatusNaDan
		INNER JOIN (
			SELECT Status.ClanID AS ClanID, MAX(Status.Datum) AS maximum_Datum
			FROM Status 
			WHERE Status.Datum BETWEEN {paramDatumOD} AND {paramDatumDO}
			GROUP BY Status.ClanID
			) AS StatusMaxDate
			ON StatusNaDan.ClanID = StatusMaxDate.ClanID 
			WHERE StatusNaDan.Datum = StatusMaxDate.maximum_Datum ) AS StatusNaDan
		ON Clan.ClanID = StatusNaDan.ClanID
	LEFT OUTER JOIN (
		SELECT
		Aktivnost.ClanID,
		SUM(Aktivnost.Bodovi) AS sum_Bodovi,
		SUM(Aktivnost.BodoviRegulativa) AS sum_BodoviRegulativa,
		SUM(Aktivnost.BodoviOpcenito) AS sum_BodoviOpcenito
		FROM Aktivnost
		WHERE Aktivnost.Datum BETWEEN {paramDatumOD} AND {paramDatumDO}
		GROUP BY Aktivnost.ClanID
		) AS AktivnostUpit
		ON Clan.ClanID = AktivnostUpit.ClanID
ORDER BY
	Clan.Prezime,
	Clan.Ime