I have developed a simple data report in my access application. I have a simple "Report Header" section with some titles and a "Body" section where I show fields coming from my recorset.
so far, so good.

Now I created a field inside "Report Footer" section, the field is a text box and its ControlSource is: "=Sum([one of my integer fields])"
but, when I open my report I get the error
Error 2589: Unvalid expression: "Sum([Distr.Cop])"

Why?