Counting multiple variables returns #VALUE

[was]

I am attempting to count the number of engineering drawings with an E in
the name in column O. Between to dates in column F.

This returns 66 if I just want to find the number of "E" drawings in
column O:

SUMPRODUCT(--(ISNUMBER(SEARCH("E",ECNT!O2:O690)))

But when I tried to add a date range for column F to the formula it
returns #VALUE:

SUMPRODUCT(--(ISNUMBER(SEARCH("E",ECNT!O2:O690))),--(ECNT!F2:F690>=DATE(2005,4,1)),--(ECNT!F2:F690<=DATE(2005,4,7)))

What gives?

Any help would be greatly appreciated.

 

[Dave Peterson]

I'd look for errors in F2:f690.

Select that range
edit|goto|special
check constants and then uncheck all but errors

If that didn't find something, then do the same for formulas.

(don't forget to look in hidden rows.)