You've created an Adobe Sign form. Click on Tools - Prepare Form and then click on "More" at the right side of the window and then on "Revert to Acrobat Form". In the future, do not tick the box that says "This document requires signatures" when creating the form.
Charlie, it may be too little, too late, but I just noticed this as I was searching for answers to a question I had. I took a look at the form. I went to Prepare Form and looked at the Properties of all your fields. Under the General Tab they were all marked as Read Only. This doesn't allow for any changes to be made. You have to uncheck the Locked box at the bottom and then uncheck Read Only. You can then lock the box again. This will have the fields show up and allow changes to be made to it.