How To Fix ARS_CMP_ATC012 - Object was changed incompatibly regarding use for custom fields (C0).

SAP Error Message - Details

• Message type: E = Error

• Message class: ARS_CMP_ATC - API Release: Compatibility Checks – ATC Messages

• Message number: 012

• Message text: Object was changed incompatibly regarding use for custom fields (C0).

What causes this issue?

Incompatible changes were detected in a development object which was
released as API to add custom fields at dedicated extension points using
key user apps (compatibility contract C0).

System Response

Each released API is checked for incompatible changes between releases
depending on the assigned compatibility contract. Those checks comprise
of <ZK>basic checks </>(e.g. detection of deleted elements) and
<ZK>domain-specific checks </>(e.g. detection of annotation changes in
CDS views) by different application components.

How to fix this error?

Each check message describes an incompatible change in a development
object which was released as API.
Undo this incompatible change by restoring the affected part of the API
in the way it was previously shipped to the customer.
Example
An extension association was removed from the projection list of a
released CDS view. If this association is used by a customer-specific
CDS view extension, this would cause ABAP dictionary activation errors
during the upgrade of the customer system.
<ZK>Check message</>: Extension association <AssociationName> was
removed.
<ZK>Remedy</>: Add the extension association to the CDS view again,
using the same alias as before.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.