Operation &1 of sequence &2 cannot be confirmed

What causes this issue?

On the following screen, you can confirm inspection point data as well
as carry out an order confirmation. However, an order confirmation is
not permitted for the current operation.

System Response

The partial and/or final confirmation indicator is not ready for input
and so, a confirmation cannot be made to production planning.
However, QM relevant inspection point data can be recorded.

Error message extract from SAP system. Copyright SAP SE.