SAP Message 63371 - Apport.unit for & for SU & not defined in Customizing

Diagnosis
You want to calculate an option rate for settlement unit &v2& based onthe relationship of the apportionment units.
Apportionment unit &v1& that is to be used for this (either thecurrently valid apportionment unit or an alternative apportionment unitfor determining option rates) is not defined in Customizing.

System Response
The system will not carry out a calculation for this settlement unit.

Procedure
Check whether you have selected the correct apportionment unit.
If yes, inform your system administrator.

Procedure for the system administrator
Create the requested apportionment unit in Customizing if necessary.