Error calling endpoint: Exception has occurred: CLR/System.Nullreferenceexception C#

Question

Guys, I’m trying to generate a spreadsheet filled with the data I have from SQL server, I can get that information right but when I call a method responsible for taking that information and recording it into an Excel spreadsheet whenever the endpoint containing that method is called take null reference error(at least that’s what I got).

I tried to debug but even marking in the responsible method with breakpoint it does not even enter so I can better understand what happens inside.

Is there any other way besides breakpoint to catch what is causing this error ?

Here’s the method I call in the controller :

public class CriarExcel
{

    private readonly EmployeeRepository _repository;

    public CriarExcel(EmployeeRepository repository)
    {
        _repository = repository;
    }
    public string PreencherExcel()
    {   
        try
        {
            ArquivoExcelEmployee arquivoExcelEmployee = new ArquivoExcelEmployee();

            Console.WriteLine("Carregando configurações...");
            var builder = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile($"appsettings.json");
            var configuration = builder.Build();

            DateTime dataHoraExtracao = DateTime.Now;
            var excelConfigurations = new ExcelConfigurations();
            new ConfigureFromConfigurationOptions<ExcelConfigurations>(
                configuration.GetSection("ExcelConfigurations"))
                    .Configure(excelConfigurations);

            Console.WriteLine("Gerando o arquivo .xlsx (Excel) com as cotações...");

            string arquivoXlsx = arquivoExcelEmployee.GerarArquivo(
                excelConfigurations, dataHoraExtracao,
                _repository.Get());
            Console.WriteLine($"O arquivo {arquivoXlsx} foi gerado com sucesso!");

             return arquivoXlsx;

        }
        catch (Exception Ex)
        {
           throw Ex;
        }
       
        
    }

}