Hi Chandan,
Its great to know your most scenarios are working. We too have tried Print Preview of the Sales Document. We are getting the Successful message on HCI but unable to get the print preview in PDF in COD. We get the error "PDF Document could not be retrieved".
Currently we are stuck in other issues and unable to look into it. However we will do it in the next few days. In case we are successful, I will surely let you know the troubleshooting steps.
Regards,
Sangeeta