Invoice contains &1 error corrections that are still to be clarified

What causes this issue?

The invoice still contains &V1& unclarfied error corrections.
Invoices of this type cannot be posted.

System Response

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

How to fix this error?

Clarify who is responsible for the error(s).
If the supplier is responsible for the error, change the correction
indicator.
If your company is responsible for the error, deselect the correction
indicator and correct the quantity to be invoiced and the amount to be
invoiced for the item.

Error message extract from SAP system. Copyright SAP SE.