SELECT Invent.codigo, Productos.descrip, SUM(Invent.saldoenivel); FROM sabia!invent INNER JOIN sabia!productos ; ON Invent.codigo = Productos.codigo; WHERE SUM(Invent.saldoenivel) = 0; GROUP BY Invent.codigo; ORDER BY Invent.codigoWhen I try to run a view based on this SQL I get a message "File 'sum.prg' does not exist"