error de sintaxis

[flaviovich]

Por eso siempre es bueno identar el script.

Código SQL:

SELECT B.Docdate, B.docduedate, B.taxdate,A.Cardcode, B.Cardname, B.docnum,
B.Acctcode, B.ocrCode, B.doctotal, C.Sumatoria
FROM (
    SELECT t1.cardcode
    FROM OCRD t0
    INNER JOIN OINV T1 ON t0.Cardcode = T1.cardcode
    WHERE t0.cardtype = 'C'
) A
LEFT JOIN (
    SELECT t1.docdate 'Fecha de Contabilizacion', t1.docduedate 'Fecha de Vencimiento',
    t1.taxdate 'Fecha de Documento', t1.Cardcode 'Codigo de Cliente',
    t1.Cardname 'Nombre de Cliente', t1.docnum 'Numero de documento', 
    t2.AcctCode 'Cuenta de Mayor', t2.OcrCode 'Centro de beneficio', t1.doctotal 'Total deuda' 
    FROM OINV t1
    INNER JOIN INV1 t2 ON t1.DocEntry = t2.Docentry
    WHERE t1.DocStatus = 'O'
) B ON A.cardcode = B.cardcode
LEFT JOIN (
    SELECT t1.cardcode, SUM(t1.doctotal) sumatoria
    FROM OCRD t0
    INNER JOIN OINV t1 ON t0.Cardcode = t1.cardcode
    WHERE t0.cardtype = 'C' AND t1.DocStatus = 'O'
    GROUP BY t1.cardcode
) C ON C.cardcode = A.cardcode
GROUP BY B.Docdate, B.docduedate, B.taxdate,A.cardcode, B.Cardname, B.docnum,
B.Acctcode, B.ocrCode, B.doctotal, C.Sumatoria
 

Solo no entiendo tu group by, donde esta el operador de agregacion, es decir, SUM, COUNT, etc.?