Curtain element Panel doesn't belong to Curtain element. In merging, you must select the version of a Curtain element that has had Panels added to it.

public static FailureDefinitionId CurtainPanelNotBelongsToElement { get; }

Public Shared ReadOnly Property CurtainPanelNotBelongsToElement As FailureDefinitionId
	Get

public:
static property FailureDefinitionId^ CurtainPanelNotBelongsToElement {
	FailureDefinitionId^ get ();
}