SAP Message PSZ1029 - Variable not allowed in tranaction currency key field

Diagnosis
You have defined "Transaction currency" as a key column AND set avariable for this characteristic.

System Response
The planning layout cannot be saved.

Procedure
To ensure free input for the transaction currency, enter "*" instead ofa variable.
If you want to permit planning in one currency only, define the"Transaction currency" characteristic as part of the general selectionand enter either a variable or a fixed value.