Several possibilities.
could there be a macro running which changes the format to text?
right click on the tab and select view code
what does format cells number say after this happens?
if you go back to the original cell does it worlk correctly?


highlite the equal sign and replace it with a new equal sign.

"LucyMR" wrote:

I'm using Excel 2003 Prof Ed. and am experiencing a similar problem as
described in previous posts, but can't find a solution. The formula works in
some cells but not in others. I have tried changing the format of the cell
and checking the formula, but excel does not even want to evaluate it, giving
the error mentioned in the subject above.

If I copy a cell that has a working formula (it displays the result), and
paste it, it's fine. Then when I edit the cell to change the criteria (e.g.
the range) then it suddenly stops evaluating and only displays the formula.
In fact, even if I only click on the cell and hit ENTER, it encounters the
same error.

btw. the formula is simple: =COUNTIF(B88:H97,"MT")

Please advise. Thanks.