Error "No reference services exist" while loading Service PO using LSMW IDOC method

Hi,

I am getting the error "No reference services exist" while loading the Service PO using LSMW IDOC method despite passing the limit values in the Limits tab. However, I can create the PO manually by entering the same data passed in IDOC. The error "Maintain Services or Limits" does appear initially while creating PO manually but goes away when I enter the Limits value under Limits tab, however IDOC is showing above error.

Can someone tell how can I get rid of this error while processing IDOC?

Thanks