net9.0 
namespace System.ServiceModel
{
    public class MessageHeaderException : ProtocolException
    {
        public bool IsDuplicate { get; }
    }
}
.NET 5.06.07.08.09.010.0
.NET Core 2.02.12.23.03.1
.NET Framework 3.03.54.04.54.5.14.5.24.64.6.14.6.24.74.7.14.7.24.84.8.1
.NET Standard 2.02.1
Information specific to net9.0
Assembly

System.ServiceModel.Primitives , Version=8.1.2.0, PublicKeyToken=b03f5f7f11d50a3a

Referencing

Your project needs a package reference to System.ServiceModel.Primitives.

Package System.ServiceModel.Primitives (8.1.2) net8.0
Platform Restrictions

The property getter is supported on all platforms.

  • Built-in API
  • Package-provided API