C# ASP.NET MVC Forms Adding Form Validation Adding Server-Side Validations Using Data Annotations

make the Name and DescriptionOfProblem properties required by adding [Required] data annotations to those properties

I added [Required] data annotation to both the properties. I am not sure what's wrong with the code.

using System.ComponentModel.DataAnnotations;

namespace IssueReporter.Models
    public class Issue
        public enum SeverityLevel

        public int Id { get; set; }
        public string Name { get; set; }
        public string Email { get; set; }
        public int DepartmentId { get; set; }
        [Display(Name = "Department")]
        public Department Department { get; set; }
        public SeverityLevel Severity { get; set; }
        public bool Reproducible { get; set; }
        [Display(Name = "Description of Problem")]
        public string DescriptionOfProblem { get; set; }

The error says "Bummer! Did you remove or change the Issue class?"