SAP Message RU459 - Operation & in sequence & cannot be confirmed by progress confirmation

Diagnosis
No progress confirmation can be created for operation &V1& in sequenceV2 because a wage slip confirmation has already been created for theoperation.
A progress confirmation after a previous wage slip confirmation is onlypossible for planned milestones.

System Response
The system does not allow you to create a progress confirmation.

Procedure
Create a wage slip confirmation for the operation.