How To Fix USMD2049 - Entity type &2, UI element &1: Table column with key field is missing

SAP Error Message - Details

• Message type: E = Error

• Message class: USMD2 - Master Data: UI Modeling

• Message number: 049

• Message text: Entity type &2, UI element &1: Table column with key field is missing

What causes this issue?

A table must have at least one table column with a key field. UI element
&V1& with the table UI element type does not have a lower-level UI
element with the UI element type <LS>Table Column with Key Field</>.

System Response

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

INCLUDE CHANGES_CANNOT_BE_SAVED OBJECT DOKU ID TX

How to fix this error?

For all higher-level entity types of the attributes you want to display
in table &V1&, create a UI element with the UI element type <LS>Table
Column with Key Field</> and enter UI element &V1& as the <LS>Higher UI
Element</>. Create a lower-level UI element for each of these UI
elements, enter the attributes in the <LS>Attr./Entity Type</> field,
and choose one of the following UI element types for this UI element:
Input field
Output field
Dropdown list box
Checkbox
Hyperlink
Text editor

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.