Diagnosis
UI element &V1 of entity type &V2& has the UI element type TableColumn with Key Field. The attribute assigned to the lower-level UIelement must therefore be an entity type that is the higher-level entitytype of another attribute. The assigned attribute is not a higher-levelentity type of one of the attributes that are assigned to entity typeV2, however.
INCLUDE CHANGES_CANNOT_BE_SAVED OBJECT DOKU ID TX

Procedure
For the lower-level UI element of UI element &V1&, enter an attributethat is a higher-level entity type. You could use entity type &V3&. Ifit is not a higher-level entity type either, enter a differentattribute.