C# There is an error in XML document (2, 2)

Question

I'm trying to deserialize the following XML :

<?xml version="1.0" encoding="UTF-8"?>
<XGResponse><Failure code="400">
    Message id &apos;1&apos; was already submitted.
</Failure></XGResponse>

through this call :

[...]
    var x = SerializationHelper.Deserialize<XMLGateResponse.XGResponse>(nResp);
[...]        

public static T Deserialize<T>(string xml)
{
    using (var str = new StringReader(xml))
    {
        var xmlSerializer = new XmlSerializer(typeof(T));
        return (T)xmlSerializer.Deserialize(str);
    }
}

to get an instance of the corresponding class :

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:4.0.30319.18052
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

using System.Xml.Serialization;

// 
// This source code was auto-generated by xsd, Version=4.0.30319.1.
// 

namespace XMLGateResponse
{

    /// <remarks/>
    [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.1")]
    [System.SerializableAttribute()]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true, Namespace = "http://tempuri.org/XMLGateResponse")]
    [System.Xml.Serialization.XmlRootAttribute(Namespace = "http://tempuri.org/XMLGateResponse", IsNullable = false)]
    public partial class XGResponse
    {

        private object[] itemsField;

        /// <remarks/>
        [System.Xml.Serialization.XmlElementAttribute("Failure", typeof(Failure))]
        [System.Xml.Serialization.XmlElementAttribute("Success", typeof(Success))]
        public object[] Items
        {
            get
            {
                return this.itemsField;
            }
            set
            {
                this.itemsField = value;
            }
        }
    }

    /// <remarks/>
    [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.1")]
    [System.SerializableAttribute()]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true, Namespace = "http://tempuri.org/XMLGateResponse")]
    [System.Xml.Serialization.XmlRootAttribute(Namespace = "http://tempuri.org/XMLGateResponse", IsNullable = false)]
    public partial class Failure
    {

        private string codeField;

        private string titleField;

        private string valueField;

        /// <remarks/>
        [System.Xml.Serialization.XmlAttributeAttribute(DataType = "NMTOKEN")]
        public string code
        {
            get
            {
                return this.codeField;
            }
            set
            {
                this.codeField = value;
            }
        }

        /// <remarks/>
        [System.Xml.Serialization.XmlAttributeAttribute()]
        public string title
        {
            get
            {
                return this.titleField;
            }
            set
            {
                this.titleField = value;
            }
        }

        /// <remarks/>
        [System.Xml.Serialization.XmlTextAttribute()]
        public string Value
        {
            get
            {
                return this.valueField;
            }
            set
            {
                this.valueField = value;
            }
        }
    }

    /// <remarks/>
    [System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.1")]
    [System.SerializableAttribute()]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true, Namespace = "http://tempuri.org/XMLGateResponse")]
    [System.Xml.Serialization.XmlRootAttribute(Namespace = "http://tempuri.org/XMLGateResponse", IsNullable = false)]
    public partial class Success
    {

        private string titleField;

        /// <remarks/>
        [System.Xml.Serialization.XmlAttributeAttribute()]
        public string title
        {
            get
            {
                return this.titleField;
            }
            set
            {
                this.titleField = value;
            }
        }
    }
}

But it raise the error There is an error in XML document (2, 2).
I've looked for a solution to this for about an hour now, but it didn't help much.

I even tried a slight change which should not do anything :

public static T Deserialize<T>(string xml)
{
    [...]
        var xmlSerializer = new XmlSerializer(typeof(T), new XmlRootAttribute(typeof(T).Name));
    [...]
}

Yet, this does prevent the error to happen. But since it only achieve to return me a XMLGateResponse.XGResponse instance fully empty (every elements/attributes are null), it's not really an improvement.

I know this kind of question There is an error in XML document (2, 2) has been discussed a lot already, but I really didn't find a solution that worked for me.

Answer 1

If you try to deserialise to the wrong type you might get the same error.
For instance if you call

Deserialize<object>(myXml)

or

Deserialize<Failure>(myXml)

---

I know it is a bad practice to answer the Q when 1)the answer is already provided and 2)the answer is not exactly what the questioner asked for; but I think it might save some time for someone else finding their way here with a problem not exactly like the questioner had.

Answer 2

XGResponse is decorated with an XmlRootAttribute that specifies a default namspace name but your document does not.

Either remove this namespace declaration or add xmlns="http://tempuri.org/XMLGateResponse" to the root element of you xml