Unable to resolve "CsvHelper.HeaderValidationException : Header with name 'field'[0] was not found"

[NajyStark]

I have been looking into different issues reporting this same error here in the issues section, but I cannot seem to find the solution. I created my CsvConfiguration adding all things I need, thinking using this may resolve the issue, but looks like is not the case. I have the latest version of CsvHelper installed (27.2.1).

I need to read a csv file with headers which has 1k rows. I have setup my method to read the csv file and return it as a List<>, but as soon as .NET is executing line 'var records = csv.GetRecords<Contact>().ToList();', it returns error "CsvHelper.HeaderValidationException : Header with name 'field'[0] was not found".

` public static List<ContactInfo> getListFromCsvFile(string location) { using (var reader = new StreamReader(location, Encoding.UTF8)) { reader.BaseStream.Position = 0;

            var config = new CsvConfiguration(CultureInfo.InvariantCulture)
            {
                Delimiter = "\t", BadDataFound = null, HasHeaderRecord = true, TrimOptions = TrimOptions.Trim, MissingFieldFound = null,
                IgnoreBlankLines = true
            };
            
            using (var csv = new CsvReader(reader, config))
            {
                csv.Context.TypeConverterOptionsCache.GetOptions<DateTime?>().NullValues.Add("null");
                csv.Context.TypeConverterOptionsCache.GetOptions<bool?>().NullValues.Add("false");
                csv.Context.TypeConverterOptionsCache.GetOptions<short?>().NullValues.Add("0");
                csv.Context.TypeConverterOptionsCache.GetOptions<decimal?>().NullValues.Add("0");
                csv.Context.TypeConverterOptionsCache.GetOptions<int?>().NullValues.Add("0");

                csv.Context.RegisterClassMap<Mappers>();
                var records = csv.GetRecords<ContactInfo>().ToList();
                return records;
            }
        }
    }`

Please let me know if anyone needs any more information.

[jamesbascle]

We'd need to see your CSV file and your class map for ContactInfo to help you with this.

[alexbereznikov]

Had the same issue today, here's what helped me - https://github.com/JoshClose/CsvHelper/issues/1348#issuecomment-508525154 https://github.com/JoshClose/CsvHelper/issues/1653#issuecomment-763608811

[ShashankDhasal]

I too am facing the same issue CsvHelper version 29.0

public static IEnumerable<T> ReadFromCsv<T>(string csv)
        {
            var conf = new CsvConfiguration(CultureInfo.InvariantCulture)
            {
                Delimiter = ",",
                HasHeaderRecord = true,
                TrimOptions = TrimOptions.Trim,
                MissingFieldFound = null
            };

            using (var stringReader = new StringReader(csv))
            using (var csvReader = new CsvReader(stringReader, conf))
            {
                return csvReader.GetRecords<T>().ToList(); // **gives exception Header with name 'FormId'[0] was not found.**
            }
        }

it is called like this ReadFromCsv<Form>(csvString).FirstOrDefault()

public class Form
	{
		public Int64 FormId { get; set; }
		public Int64 FormTypeId { get; set; }
	}

csvString = "FormId,FormTypeId 22,3"