Element &1 of CDS view &3 is deprecated. Use element &2 instead.

What causes this issue?

In <LB>ABAP for Key Users</>, use of other objects is restricted to
objects which were
released as API for <ZK>Use in Key User Apps</> or
created by key user apps and marked for use by other key user apps.
IF &[SWITCH]S4H_DOCU_ON_PREMISE& = 'X'.
For further details, see
<DS:ABEN.ABAP_VERSIONS>ABAP Language Versions</>.
ENDIF.

System Response

If the edited object uses a formerly released but now deprecated CDS
view element, this results in a syntax warning. This CDS view element
can either be a field or a public association.

How to fix this error?

Replace the use of deprecated CDS view element &V1& by its successor
&V2&.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.