xfdf called "wrong document type"

I am experimenting with E-sign.  I go to "Create e-sign template" and select a xfdf file.  This is file that I use as a form.  I fill the data in the form from Microsoft Access, and send to the client for signature.  I thought maybe using this doc as a template in adobe would be better.  But it rejects the choice of the xfdf file as a "wring document type".  Wrong data type to create a template?  Does not make sense to me.