DataContractJsonSerializer exception

Question

I am getting this error when using my class.

Error

Expecting element 'root' from namespace ''.. Encountered 'None' with name '', namespace

My Class

[DataContract]
public class EntryData
{
    [DataMember]
    public string EntryId { get; set; }

    [DataMember]
    public string EmailAddress { get; set; }

    [DataMember]
    public string StatusCode { get; set; }

    [DataMember]
    public string TotalVoteCount { get; set; }

    public static T Deserialise<T>(string json)
    {
        var obj = Activator.CreateInstance<T>();
        using (var memoryStream = new MemoryStream(Encoding.Unicode.GetBytes(json)))
        {
            memoryStream.Position = 0;
            var serializer = new DataContractJsonSerializer(obj.GetType());
            obj = (T)serializer.ReadObject(memoryStream); // getting exception here                    
            return obj;
        }
    }
}

USAGE

string responseJson = new StreamReader(HttpContext.Current.Request.InputStream).ReadToEnd();
var results = EntryData.Deserialise<EntryData>(response)

I have seen online that it has to do with the memoryStream position BUT as you can see i am setting it to the beginning.

Please help.

Json going to handler

I don't set StatusCode or TotalVoteCount when passing JSON in. I don't think this is the problem though.

{
    "EntryId":"43",
    "EmailAddress":"[email protected]"
}

ANSWER

Instead of using Deserialize method in my class I am using now this.

//commented out this code.        
string responseJson = new StreamReader(HttpContext.Current.Request.InputStream).ReadToEnd();
var results = EntryData.Deserialise<EntryData>(response)

// this is the way to go using JavaScriptSerializer   
var serializer = new JavaScriptSerializer();
var results = serializer.Deserialize<EntryData>(response);

Answer 1

Could it be caused by your JSON names not matching your property names in C#?

My understanding is that

{
     "FirstName" : "Mark"
}

Would be able to deserialize into:

[DataContract]
public class Person 
{    
     [DataMember]
     public string FirstName {get; set;}
}

but this wouldn't be able to serialize

{
     "Name" : "Mark"
}

unless you changed your C# class to have an explicit name for the DataMember

[DataContract]
public class Person 
{    
     [DataMember(Name="Name")]
     public string FirstName {get; set;}
}

I'm not sure which error this would cause though. I Don't have enough first hand experience.