title: DeserializeObject Error: Value cannot be null
body: <p>I'm using the plugin <code>Newtonsoft.Json</code> in my xamarin.forms application for serializing and deserializing an object of typr <code>Form</code></p>
  
  <pre><code>public class Form
  {
      [JsonProperty("id")]
      public int id { set; get; }
  
      [JsonProperty("title")]
      public string title { set; get; }
  
      [JsonProperty("body")]
      public string body { set; get; }
  
      [JsonProperty("department_id")]
      public string department_id { set; get; }
  
      [JsonProperty("fields")]
      public List&lt;FormField&gt; fields { set; get; }
  }
  
  public class FormField
  {
      [JsonProperty("id")]
      public int id { set; get; }
  
      [JsonProperty("title")]
      public string label { set; get; }
  
      [JsonProperty("inputtype")]
      public string inputtype { set; get; }
  
      [JsonProperty("key")]
      public string key { set; get; }
  
      [JsonProperty("item_order")]
      public int order { set; get; }
  
      [JsonProperty("required")]
      public bool isRequired { set; get; }
  
      [JsonProperty("enabled")]
      public bool isEnabled { set; get; }
  
      public CellCustom fieldObject { set; get;}
  
  
      public FormField()
      {
          fieldObject = CreateInstance() as CellCustom;
      }
  
      private object CreateInstance()
      {
          return Activator.CreateInstance(Type.GetType("Hura.Models.Cells." + inputtype));
      }
  
      public Cell createCell()
      {
          return fieldObject.createCell();
      }
  }
  </code></pre>
  
  <p>here is the deserializing code</p>
  
  <pre><code>string str= @"{""id"": 17,""title"": ""testform"",""body"": ""null"",""department_id"": 5,""fields"": [{""id"": 28,""title"": ""null"",""inputtype"": ""text"",""key"": ""f1474532070512"",""item_order"": 1,""required"": true,""enabled"": true}]}";
  Form tstfrm = JsonConvert.DeserializeObject&lt;Form&gt;(str);
  MainPage = new FillForm(tstfrm); 
  </code></pre>
  
  <p>But when I run this code, it gives me the error <code>System.ArgumentNullException: Value cannot be null. Parameter name: type</code> even when I don't have any fields named "type" in my JSON object!</p>
  
  <p>What is the problem in my code, and how can I solve it?</p>