Deletion Indicator cannot be unset" error message in PO

Hi Experts!

I have a PO in which I deleted a line item, which has been invoice verified, delivered, etc. Now when I choose to unblock/undelete the line item, it give me error message: "Deletion Indicator cannot be unset". Is this a major problem or can it be fixed. Any information would be greatly appreciated. Urgent! Thank you for your time!

Best Regards,

WC