title: WCF Service cannot return JSON of List of objects
body: <p>I have an object defined as below.  From my WCF Service I can return a List with no problems, but when I try to return as Json, it returns zero bytes.  No error.</p>
  
  <p>I have about 80 other methods in this project with no problems, but this one will simply not convert.   I could change Serializer to NewtonSoft but this is nearing the end of this project. I've never seen this issue before.</p>
  
  <p>My objectX is as below, is there something I've missed?  </p>
  
  <pre><code>public class objectX
      {
          public string CompanyName { get; set; }
          public string Username { get; set; }
          public string BranchName { get; set; }
          public Nullable&lt;decimal&gt; Amount { get; set; }
          public int Id { get; set; }
          public int ClientId { get; set; }
          public int UserId { get; set; }
          public int TypeId { get; set; }
          public int Credits { get; set; }
          public System.DateTime InvoiceDate { get; set; }
          public string Notes { get; set; }
          public Nullable&lt;int&gt; LinkedId { get; set; }
          public string Status { get; set; }
          public Nullable&lt;System.DateTime&gt; DateProcessed { get; set; }
          public Nullable&lt;int&gt; ProcessedBy { get; set; }
          public int BranchId { get; set; }
          public Nullable&lt;System.DateTime&gt; CreatedOn { get; set; }
          public Nullable&lt;int&gt; CreatedBy { get; set; }
          public Nullable&lt;System.DateTime&gt; ModifiedOn { get; set; }
          public Nullable&lt;int&gt; ModifiedBy { get; set; }
    }
  </code></pre>
  
  <p>Here is the contract:</p>
  
  <pre><code>    [OperationContract]
      [WebInvoke(Method = "GET",
      UriTemplate = "objectX/Read/{clientId}/{branchId}/{statuses}/{dateTime}",
      ResponseFormat = WebMessageFormat.Json)]
      List&lt;objectX&gt; objectXRead(string clientId, string branchId, string statuses, string dateTime);
  </code></pre>