During upgrade, Revit discovered that the highlighted elements were marked with tags of the wrong category. These tags were deleted.

public static FailureDefinitionId ElementCategoryChangeInvalidatesTagUpgrade { get; }

Public Shared ReadOnly Property ElementCategoryChangeInvalidatesTagUpgrade As FailureDefinitionId
	Get

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