I have a problem like [this.](https://stackoverflow.com/questions/11072877/an-exception-of-type-automapper-automappermappingexception-occurred-in-automap) But this answer it didn't work for me.

I am working on a little project. I have two domain model (Post, Source):

```
public class Post
{
    public Post()
    {
        Sources = new HashSet<Source>();
    }

    public int Id { get; set; }
    public string Title { get; set; }
    public string About { get; set; }
    public bool IsPublished { get; set; }
    public bool IsFinished { get; set; }
    public DateTime? CreatedOn { get; set; }
    public int? CreatedBy { get; set; }

    public virtual ICollection<Source> Sources { get; set; }
}

public class PostViewModel
{
    public int Id { get; set; }
    public string Title { get; set; }
    public string About { get; set; }
    public bool IsPublished { get; set; }
    public bool IsFinished { get; set; }
    public DateTime? CreatedOn { get; set; }
    public int? CreatedBy { get; set; }

    public virtual ICollection<SourceViewModel> Sources { get; set; }
}   

public ActionResult Edit(int id)
{
    Mapper.CreateMap<Post, PostViewModel>()
        .ForMember(dest => dest.Id, opt => opt.MapFrom(src => src.Id))
        .ForMember(dest => dest.Title, opt => opt.MapFrom(src => src.Title))
        .ForMember(dest => dest.About, opt => opt.MapFrom(src => src.About))
        .ForMember(dest => dest.IsPublished, opt => opt.MapFrom(src => src.IsPublished))
        .ForMember(dest => dest.IsFinished, opt => opt.MapFrom(src => src.IsFinished))
        .ForMember(dest => dest.CreatedOn, opt => opt.MapFrom(src => src.CreatedOn))
        .ForMember(dest => dest.CreatedBy, opt => opt.MapFrom(src => src.CreatedBy))
        .ForMember(dest => dest.Sources, opt => opt.MapFrom(src => src.Sources))
        .ReverseMap();

    var Post = _PostService.Get(id);

    var model = Mapper.Map<Post, PostViewModel>(Post);

    return View(model);
}

```

But I am getting an error like that: 

> 
> An exception of type 'AutoMapper.AutoMapperMappingException' occurred in AutoMapper.dll but was not handled in user code
> 
> 
> 

Source domain object and `SourceViewModel` similar `Post` and `PostViewModel`.

Hopefully this explains my problem. How can I resolve to this problem?