Message SAP WXPA001 - Characteristic &2 was not assigned

Diagnosis
You are defining a read interface between MAP and the application &V1&.You have selected a planning scenario and a planning step combination.To be able to use the interface you need to be on the most detailedlevel of the planning step. Either you have not selected all theplanning characteristics in the characteristics selection, or you haveselected a key figure for which a unit has not yet been assigned.

System Response
The interface is incorrect and cannot be used

Procedure
Maintain all the planning characteristics in the characteristicsselection that have the F4 help option.