SO-52751177-Previous

main.cs

using System.Linq;
using ServiceStack;
using ServiceStack.Text;
using System;

JsConfig.IncludeNullValues = false;
JsConfig.ExcludeDefaultValues = false;
JsConfig<Guid>.SerializeFn = guid => guid.ToString();
var tt = new { Name="Fred", Value=Guid.Empty, Value2=Guid.NewGuid() };
var test = tt.ToJson();
Console.WriteLine(test);

packages.config

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="ServiceStack.Text" version="5.2.0" targetFramework="net45" />
  <package id="ServiceStack.Client" version="5.2.0" targetFramework="net45" />
  <package id="ServiceStack.Interfaces" version="5.2.0" targetFramework="net45" />
</packages>