Can't [Action] because Family '[Family Name]' is different in the two documents. Update the documents to contain the same version of the Family.
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 26.4.0.0 (26.4.0.0)
Syntax
C#
public static FailureDefinitionId CannotCopyFamilyName { get; }