Inconsistent Formula
 

If K21 contains =IF($B21=$B20,K20,"") and displays 4,
and L21 contains =IF(ISNUMBER(K21),SUM(C21:K21),"")
then L21 will display 36 with a triangle on it.

If I over type that 4 in K21 to be 4, then the triangle goes away.

If I select the !, I find it is "Inconsistent Formula". I select
"Help on this error", and I get a blank help window.


My real problem may be that I am going about the "Don't show me data
if I haven't created this row yet" issue.


What should I be doing?