The MONTH function produces an error with non-numeric cells that poisons
the calculation. Expand to either

=SUMPRODUCT((IF(ISNUMBER(C2:C40),MONTH(C2:C40)=MON TH(A1)))*((B2:B40="A")+(B2:B40="B"))*(((D2:D400)+ (E2:E400)+(F2:F400)+(G2:G400))0))
or
=SUM((IF(ISNUMBER(C2:C40),MONTH(C2:C40)=MONTH(A1)) )*((B2:B40="A")+(B2:B40="B"))*(((D2:D400)+(E2:E40 0)+(F2:F400)+(G2:G400))0))

Either must be array entered (Ctrl-Shift-Enter). SUMPRODUCT usually
does not require array entry, but it does in this case becase of the
MONTH function.

Jerry

JustMe602 wrote:

I am not getting the suggested

SUMPRODUCT function to work?

JustMe.