& can only be included in the profile with &

What causes this issue?

You have selected the weighting group but not the forecast
model.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

If you want to include a weighting group in the profile, then select
the forecast model.

Error message extract from SAP system. Copyright SAP SE.