PDF Generation error on purchase order approval notification

Hi all,

We are on 11i and recently did a customization for contingent workers to be able to raise purchase documents. The solution is that contingent workers will open and fill purchase document and save it. An employee will then review it and submit for approval.

We made code changes at all possible stages to accommodate the solution in terms of forms to pull up contingent workers to be added as buyers, for them to be able to raise purchase order, save them etc.,

Everything seems to be working fine except the fact that when a PO is submitted through this route, pdf generation step on the workflow is failing and hence final approving authority is not able to view the PO pdf.