The parameters of the keynote tag are empty because the keynoted linked element uses a different keynote file.
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 26.2.0.0 (26.2.0.0)
Syntax
C#
public static FailureDefinitionId KeynoteOnLinkWithDifferentKeynoteFile { get; }