PO Number is not updating on AR Credit Memo

Hello Team,

We are receiving an error while updating the PO Number in AR Credit Memo. It works perfectly fine when we are doing the update in Invoice but when we are trying to update the PO Number in credit memo it displays the following error:

Due to this we are not able to update the PO Number in AR CM. Please let me know how can we resolve this problem.

Thanks!

Harsh