I have an invoice in a 'Flagged Externally' state, and I can't change or approve it. What does that mean?

This message usually appears when it’s an older invoice, and is already paid in your Accounts Payable hub (Sun, etc.). The user in Finance department is tiding up Invoices in Purchase Plus, moving the invoice from ‘Flagged’, to ‘Reconciled’, to ‘Processed’ state without resending the Invoice to the Accounts Payable hub as it has been paid already.

An operational approver will be able to action/view the invoice when the ‘Awaiting My Approval’ check box is unticked.

Checking the audit log of the invoice in question will show the time stamp and Username if an audit or investigation is required.