APP-PO-14440: Quantity ordered cannot be less than quantity encumbered. Unreserve the funds, reduce

Hi Team,

While changing the PO line level quantity, we are getting below error message,

"APP-PO-14440: Quantity ordered cannot be less than quantity encumbered. Unreserve the funds, reduce the quantity and re-reserve the funds"

This PO was created when we had encumbrance accounting which we later discontinued.

Could you please help us know any way to update this PO qty ?

Best REgards

AB