FormServer Exception ALC-FRM-001-013 (LiveCycle ES 8.2)

Hi

Can anyone tell me what "XFA template Model is empty" means in this exception? I'm trying to render a xdp through Form Server.

ERROR [FormServerException] ALC-FRM-001-013: XMLFormFactory, PAexecute failure: "(com.adobe.document.xmlform.ReturnStatus@11d16b9) XMLForm, load : 12309, XFA template Model is empty."

Thanks