SAP Message /MAP/F109 - Exit parameter &2 for source char. &1 is initial or does not exist

Diagnosis
The characteristic &V2& was defined in the parameter group as a sourcecharacteristic. For each source characteristic, you must enter a valuethat this characteristic should adopt. For the characteristic &V2&,enter the value using the exit parameter &V1&.
This parameter does not exist.

System Response
The system cannot execute the planning function.

Procedure
Remove the characteristic &V2& in the definition of the planningfunction from the list of source characteristics or enter the value ofthe source characteristic in the parameter group for the exit parameterV1.
Note:
If you want the source characteristic to be initial, the exit parameterV1 must also be initial.