I have a data set with 2 column headings.

I can sum all the data where row 2 = 0
=SUMPRODUCT(('Weekly Hrs'!L4:S4=0)*'Weekly Hrs'!L8:S19)
and I can sum all the data where row 1 = Phase!A5
=SUMPRODUCT(('Weekly Hrs'!L5:S5=Phase!A5)*'Weekly Hrs'!L8:S19)

However, when I try and do both: ie: sum all data where row 2 = 0 and row 1 = Phase!A5
=SUMPRODUCT(('Weekly Hrs'!L5:S5=Phase!A5)*('Weekly Hrs'!L4:S4=0),'Weekly Hrs'!L8:S19)
I get a #VALUE error: a value used in the formula is of the wrong datatype.

Any suggestions on where I'm going wrong please?

Design Test Test
0 1 1 1
4 4 3 3
1 1 2 1
0 2 1 3