No variant-creating characteristics could be determined for class &

What causes this issue?

No characteristics could be determined with the attribute
"variant-creating" for the class entered (generic material or material
group).
In material group hierarchy maintenance, you can flag a characteristic
as variant-creating if, when assigning the characteristic to the
material group/material group hierarchy level or to the generic
material, you set the usage indicator accordingly.

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?

Set the usage indicator for two characteristic assignments at most.
If variant-creating characteristics have already been assigned, but
were not found, this may be because you have not entered a material
group within the hierarchy for which the variant-creating
characteristics are known. Try choosing a lower material group level.

Error message extract from SAP system. Copyright SAP SE.