SAP Message RMSL288 - Package label list with key &1 already exists

Diagnosis
A package label list with this key already exists.
The key of the package label list is made up of the base quantity withunit and a number. The number helps you differentiate between multiplelabel lists with the same base quantity.

System Response
The system does not create a new package label list for this key.

Procedure
When you create the package label list, choose a different base quantityor a different number.