InvalidOperationException: The specified type was not recognized

Question

Trying to deserialize this XML to C# but unable to find the cause of the error.

<PaymentMethod xmlns:d2p1="http://www.w3.org/2001/XMLSchema-instance" d2p1:type="GenericPaymentMethod">
      <Amount>158.83</Amount>
      <CurrencyCode>None</CurrencyCode>
      <CurrencyCodeAlpha>USD</CurrencyCodeAlpha>
      <AccountNumber>************1001</AccountNumber>
      <UtcExpiration>2023-06-30T23:59:59</UtcExpiration>
      <PaymentMethodSubtype>MC</PaymentMethodSubtype>
      <AccountHolderName>John Doe</AccountHolderName>
      <QuotedAmount>158.83</QuotedAmount>
      <QuotedCurrencyCode>None</QuotedCurrencyCode>
      <QuotedCurrencyCodeAlpha>USD</QuotedCurrencyCodeAlpha>
      <AccountNumberId>24</AccountNumberId>
      <TokenId>3174119969340463143</TokenId>
   </PaymentMethod>

        [Serializable, XmlRoot(ElementName = "PaymentMethod")]
        public class PaymentMethod
        {
            [XmlAttribute(AttributeName = "type", Namespace = "http://www.w3.org/2001/XMLSchema-instance")]
            public string Type { get; set; }
            [XmlAttribute(AttributeName = "d2p1", Namespace = "http://www.w3.org/2000/xmlns/")]
            public string D2p1 { get; set; }
            [XmlElement(ElementName = "Amount")]
            public string Amount { get; set; }
            [XmlElement(ElementName = "CurrencyCode")]
            public string CurrencyCode { get; set; }
            [XmlElement(ElementName = "CurrencyCodeAlpha")]
            public string CurrencyCodeAlpha { get; set; }
            [XmlElement(ElementName = "AccountNumber")]
            public string AccountNumber { get; set; }
            [XmlElement(ElementName = "UtcExpiration")]
            public string UtcExpiration { get; set; }
            [XmlElement(ElementName = "PaymentMethodSubtype")]
            public string PaymentMethodSubtype { get; set; }
            [XmlElement(ElementName = "AccountHolderName")]
            public string AccountHolderName { get; set; }
            [XmlElement(ElementName = "QuotedAmount")]
            public string QuotedAmount { get; set; }
            [XmlElement(ElementName = "QuotedCurrencyCode")]
            public string QuotedCurrencyCode { get; set; }
            [XmlElement(ElementName = "QuotedCurrencyCodeAlpha")]
            public string QuotedCurrencyCodeAlpha { get; set; }
            [XmlElement(ElementName = "AccountNumberId")]
            public string AccountNumberId { get; set; }
            [XmlElement(ElementName = "TokenId")]
            public string TokenId { get; set; }
        }

Error: InvalidOperationException: The specified type was not recognized: name='GenericPaymentMethod', namespace='', at .

Answer 1

Here is solution :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
namespace ConsoleApplication33
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XmlReader reader = XmlReader.Create(FILENAME);
            XmlSerializer serializer = new XmlSerializer(typeof(PaymentMethod));

            PaymentMethod paymentMethod = (PaymentMethod)serializer.Deserialize(reader);
 

        }
    }
    [XmlInclude(typeof(GenericPaymentMethod))]
    public class PaymentMethod
    {
    }
    [Serializable, XmlRoot(ElementName = "PaymentMethod")]
    public class GenericPaymentMethod : PaymentMethod
    {
        [XmlAttribute(AttributeName = "type", Namespace = "http://www.w3.org/2001/XMLSchema-instance")]
        public string Type { get; set; }
        [XmlAttribute(AttributeName = "d2p1", Namespace = "http://www.w3.org/2000/xmlns/")]
        public string D2p1 { get; set; }
        [XmlElement(ElementName = "Amount")]
        public string Amount { get; set; }
        [XmlElement(ElementName = "CurrencyCode")]
        public string CurrencyCode { get; set; }
        [XmlElement(ElementName = "CurrencyCodeAlpha")]
        public string CurrencyCodeAlpha { get; set; }
        [XmlElement(ElementName = "AccountNumber")]
        public string AccountNumber { get; set; }
        [XmlElement(ElementName = "UtcExpiration")]
        public string UtcExpiration { get; set; }
        [XmlElement(ElementName = "PaymentMethodSubtype")]
        public string PaymentMethodSubtype { get; set; }
        [XmlElement(ElementName = "AccountHolderName")]
        public string AccountHolderName { get; set; }
        [XmlElement(ElementName = "QuotedAmount")]
        public string QuotedAmount { get; set; }
        [XmlElement(ElementName = "QuotedCurrencyCode")]
        public string QuotedCurrencyCode { get; set; }
        [XmlElement(ElementName = "QuotedCurrencyCodeAlpha")]
        public string QuotedCurrencyCodeAlpha { get; set; }
        [XmlElement(ElementName = "AccountNumberId")]
        public string AccountNumberId { get; set; }
        [XmlElement(ElementName = "TokenId")]
        public string TokenId { get; set; }
    }
}