Diagnosis
At least one dunning header from the dunning proposal run is locked.Therefore, the capacity planning could not be executed correctly.

System Response
Only dunning headers not locked by another transaction can be updatedbased on the capacity planning (for example, set alternative collectionstep).

Procedure
Make sure that the new dunning headers created are not locked by onlineprocessing (for example, by reversal from the dunning history).
To ensure a correct adherence to the upper levels according to capacityplanning, you have to delete the dunning proposal and create it again.