Invoice still contains at least one correction still to be clarified

What causes this issue?

The system tried to post the invoice. This may have been online, in the
background, or in the EDI/SOA inbound.
The invoice contains at least one item which has been corrected and for
which the correction is flagged as requiring clarification.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

The invoice cannot be posted.
If the invoice was checked by the system in the background or in the
EDI/SOA inbound, the system parked the invoice.

How to fix this error?

Process the invoice and clear up any unclarified corrections, by telling
the system whether the supplier or your company was responsible for the
variance.
If this message appeared online, and you cannot clarify the error
straightaway, we recommend you park the invoice.

Error message extract from SAP system. Copyright SAP SE.