No class types defined

What causes this issue?

You want to set a <DS:GLOS.class_type>class type</>, but no class types
are defined. At least one class type must exist for each classifiable
object before it can be classified. You define Class types in
Customizing for the Classification System.

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?

Have the class type defined by an authorized person in Customizing for
<ZH>Classification</>. Detailed information on how to define class
types can be found in Customizing for <ZH>Classification</>:
<DS:SIMG.SIMG_CFMENUO000O1CL>Proceed</>

Error message extract from SAP system. Copyright SAP SE.