Circular Reference Error Message

[jkgm]

This formula might be the problem for the error message.

SUMPRODUCT((MOD(COLUMN(C3:CO3)-COLUMN(OFFSET(C3:CO3,,,1,1)),3)=0)*C3:CO3)

I have other cells with the same formula (but with different range i.e. D3:CP3), yet it doesn't have circular reference error message.

[martindwilson]

what are you actually trying to sum ie what cells

[martindwilson]

i dont see the point of the offset, that formula is summing every 3rd cell c3,f3,i3........
so
=SUMPRODUCT((MOD(COLUMN($C$3:$CO$3),3)=0)*($C$3:$CO$3))