Monolithic Stairs without Treads can't have Risers. Riser Thickness for Stairs Type was automatically set to zero.
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 26.4.0.0 (26.4.0.0)
Syntax
C#
public static FailureDefinitionId RiserThicknesssResetToZero { get; }