The MRP type & requires forecasting data to be maintained

What causes this issue?

You have used an <DS:GLOS.MRP_type>MRP type</> for which the
<LS>Forecast indicator</> has been set to <LS>Obligatory forecast</> in
Customizing for <LS>Consumption-Based Planning</> in <LS>Check MRP
types</>. This makes it mandatory to maintain forecasting data for the
material. However, you have not yet maintained this data.

System Response

You may not update the data for the material.

How to fix this error?

Maintain the data for the user department <LS>Forecasting</> for the
material concerned.

Error message extract from SAP system. Copyright SAP SE.