Serialize and deserialize an object (There is an error in XML document (0, 0).)

I am trying to serialize and then deserialize an object. Serialization works ok, but deserialization throws a

System.InvalidOperationException : There is an error in XML document (1, 1).

  ----> System.Xml.XmlException : Data at the root level is invalid. Line 1, position 1.

The serialized xml looks OK:

<?xml version="1.0" encoding="utf-16"?>

<Data xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" Id="1" Status="OK" xmlns="http://biz.si/Project/v0100/Data.xsd">

    <DataGroup Type="SomeType">AAEC</DataGroup>

</Data>

The encoding is utf-16, which is OK, but I suspect there is an encoding problem during deserialization. Now the code is running in test environment (unit tests) but the serialized xml will be sent to a web service.

This is my code:

[TestFixture]

public class Foobar

{

    [Test]

    public void Test()

    {

        var d = new Data

        {

            Id = "1",

            Status = "OK",

            DataGroup = new DataGroup

            {

                Type = "SomeType",

                Value = new byte[] { 0x00, 0x01, 0x02 }

            }

        };



        var serialized = Serialize(d);

        var deserialized = Deserialize(serialized);    // exception is thrown here.



        Debug.WriteLine("ok");

    }



    private XmlNode Serialize(Data data)

    {

        XmlSerializer xsSubmit = new XmlSerializer(typeof(Data));

        StringWriter sww = new StringWriter();

        using (XmlWriter writer = XmlWriter.Create(sww))

        {

            xsSubmit.Serialize(writer, data);

            var xml = sww.ToString();

            var xmlDocument = new XmlDocument();

            xmlDocument.LoadXml(xml);

            return xmlDocument;

        }

    }



    private Data Deserialize(XmlNode xmlData)

    {

        XmlSerializer xmlSerializer = new XmlSerializer(typeof(Data));

        MemoryStream memoryStream = new MemoryStream(Encoding.Default.GetBytes(xmlData.InnerText));

        return (Data)xmlSerializer.Deserialize(memoryStream);

    }

}



[XmlRoot(Namespace = "http://biz.si/Project/v0100/Data.xsd", IsNullable = false)]

[XmlType(AnonymousType = true)]

public class Data

{

    [XmlAttribute]

    public string Id { get; set; }



    [XmlAttribute]

    public string Status { get; set; }



    [XmlElement("DataGroup")]

    public DataGroup DataGroup { get; set; }

}



[XmlType(AnonymousType = true)]

public class DataGroup

{

    [XmlAttribute]

    public string Type { get; set; }



    [XmlText(DataType = "base64Binary")]

    public byte[] Value { get; set; }

}