When using Digital FDile pro With A DataAssist insert page, you need to rebind all of the form fields in the Insert Record Server Behavior after applying DFP.
double Click the Insert Record Server Behavior and select each Database Column that will get a value. Click the lightning bolt and expand the form collection. Then Select the corresponding form element.
This modify the code for the binding and change it from using the Request.Form Collection to using the WA_UploadObj.Form Collection instead.