Configuration class &1 is not supported; see long text

What causes this issue?

The configuration class is not supported when the one of the following
conditions is not fulfilled:
The <ZK>characteristics </>were not created using <ZK>New Characteristic
Value Storage</>
The characteristics are not included in the transaction <ZK>WRFCHVALTYPE
</>.

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?

Use only those <ZK>Characteristics</> which were created using <ZK>New
Characteristic Value Storage<(>,<)></> or include the characteristics in
the transaction <ZK>WRFCHVALTYPE</>.

Procedure for System Administrators

What causes this issue?

The <ZK>Characteristic</>s are not supported when the one of the
following conditions is not fulfilled:
You are using <ZK>Characteristic </>which were not created using <ZK>New
Characteristic Value Storage</>
The characteristics is not included in the transaction <ZK>WRFCHVALTYPE
</>

Error message extract from SAP system. Copyright SAP SE.