with the error report
=IIf(subcontracts.Report.HasData,subcontracts.Report!SumOfEstimatedCost,0) + IIf([equipment/rentals].Report.HasData,[equipment/rentals].Report!SumOfInvoiceAmount,0)+ IIf([materialrecap].report.hasdata,[materialrecap].report!sumamountspent,0) +...