How To Fix SDDIC_ADT_DDLX077 - Cannot annotate '&1'. The type of the annotated entity is not supported

SAP Error Message - Details

• Message type: E = Error

• Message class: SDDIC_ADT_DDLX - Messages for CDS Metadata Extension

• Message number: 077

• Message text: Cannot annotate '&1'. The type of the annotated entity is not supported

What causes this issue?

The type of the annotated entity is not supported.
With the "ANNOTATE ENTITY" syntax, the following types are supported:
Views
View Entities
Projection Views
Abstract Entities
Hierarchies

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.