Fillable form not allowing edits after being sent to someone as an attachment

I was using a fillable form, that I filled out, and sent to someone as an attachment for them to add information to.  Once the recipient received  the form she was not allowed to edit or sign the form that was sent to her.  This same form was sent to others and the problem I am experiencing did not occur with the others, their form was editable.  Would having different versions of Adobe cause this problem?