Enhancement Category

What causes this issue?

System Response

Structures and tables that were defined by SAP in ABAP Dictionary can be
enhanced subsequently by customers using Customizing includes or append
structures. The enhancements do not only refer to structures/tables
themselves, but also to dependent structures that adopt the enhancement
as an include or referenced structure.
You must select an enhancement category for the following reason: In
programs where there is no active Unicode check, enhancements to tables
and structures can cause syntax and runtime errors during type checks
and particularly in combination with deep structures.

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.