C# 'Object reference not set' error when working with lists within a class

Question

This one will be very easy for you pros - but I've now wasted hours on it myself. Here's a simplified version of what I'm trying to do:

(1) I have an 'Employment' class which can store 3 strings [EmployerName], [JobTitle] and [PeriodOfEmployment]. I am successfully able to create an instance of Employment and populate it with example entries.

(2) I want to populate a wrapper class called 'CurriculumVitae' which contains a [PersonName] string plus a List variable containing all Employments ever held by the person. I want to use a loop to add instances of Employment to the instance of CurriculumVitae, so that the CurriculumVitae class ends up holding a person's full job history in its EmploymentsList.

(3) In Visual Studio am getting the error message:

System.NullReferenceException: 'Object reference not set to an instance of an object.'
CurriculumVitae.EmploymentsList.get returned null.'.

My simplified code is:

using System;
using System.Collections.Generic;

namespace CurriculumVitaeExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var CurriculumVitae = new CurriculumVitae();
            CurriculumVitae.Open();
        }
    }
}

My Employment class looks like this:

public class Employment
{
    public string EmployerName { get; set; }
    public string JobTitle { get; set; }
    public string PeriodOfEmployment { get; set; }
}

My CurriculumVitae class tries to make use of the Employment class in a List, like this:

public class CurriculumVitae //(version 1)
{
    public string PersonName { get; set; }
    public List<Employment> EmploymentsList { get; set; }

    // Open method:
    public void Open()
    {
        Employment Employment = new Employment();

        Employment.EmployerName = "McDonalds";
        Employment.JobTitle = "Ice Cream Guru";
        Employment.PeriodOfEmployment = "Jan 2019 - Present";

        this.EmploymentsList.Add(Employment);
    }

}

I also tried adding a constructor for the EmploymentsList within the CurriculumVitae class but it didn't help:

public class CurriculumVitae //(version 2)
{
        // Constructor:
        public CurriculumVitae()
        {
            List<Employment> EmploymentsList = new List<Employment>();
        }
        ...
}

Answer 1

Change the name of CurriculumVitae variable to curriculumVitae

static void Main(string[] args)
{
    var curriculumVitae = new CurriculumVitae();
    curriculumVitae.Open();
}

and Employment to employment

public void Open()
{
    Employment employment = new Employment();
    employment.EmployerName = "McDonalds";
    employment.JobTitle = "Ice Cream Guru";
    employment.PeriodOfEmployment = "Jan 2019 - Present";

    this.EmploymentsList.Add(employment);
}

And finally you must initialize EmploymentsList like this in version1

public List<Employment> EmploymentsList { get; set; } = new List<Employment>();

or in constructor in version2

public CurriculumVitae()
{
    this.EmploymentsList = new List<Employment>();
}