Material/plant &/& can only be costed with unit costing

What causes this issue?

The material can only be costed in unit costing.
The <DS:DE.CK_EKALREL>With quantity structure</> indicator in the
costing view of the material master record is not set.

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 normally want to cost this material in a
<DS:GLOS.cost_estimate_with_quantity_structure>cost estimate with
quantity structure</>, set the <LS>With quantity structure</> indicator
in the material master record.

Error message extract from SAP system. Copyright SAP SE.