No views exist or only one view exists

What causes this issue?

You want to limit the characteristics list on the value assignment
screen to a particular <DS:GLOS.organizational_area>organizational
area</>.
However, your class has either no organizational areas or only one.

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?

Check whether you want to group the characteristics of the class by
organizational area.
For example, you can define that certain characteristics are relevant
to design, or that certain other characteristics are only relevant to
sales.
For information on how to define organizational areas, see document
CA - Classification.

Error message extract from SAP system. Copyright SAP SE.