PO Approval Error: Charge account is invalid

Hi,

We are facing the below error when we are trying to approve the PO.

All accounts related to the PO are active and none of the accounts are end dated or disabled but still we are facing the error.

Error:    Charge account is invalid

Cause:        The charge account that you entered is invalid. 

Action:        Enter a valid charge account.

on distribution 1 of shipment 1 of line 1

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Error:    Budget account is invalid

Cause:        The budget account that you entered or that was derived is invalid. 

Action:        Enter a valid budget account.

on distribution 1 of shipment 1 of line 1

+--------------------------------------------------------------------------+

Any help is much appreciated.