Can not upload image with null Reference exception

[trktuhin]

My code is completely similar to yours. I have only one issue testing the photo upload api. It seems like my api is not getting a IFormFile object from the body of the request. Here's the proof:
This is the action:
` [HttpPost]
public async Task Upload(int vId,IFormFile fileStream)
{
var vehicle = await this.repository.GetVehicle(vId, hasAdditional: false);
if (vehicle == null)
return NotFound();
var uploadsFolderPath = Path.Combine(host.WebRootPath, "uploads");
if (!Directory.Exists(uploadsFolderPath))
Directory.CreateDirectory(uploadsFolderPath);
var fileName = Guid.NewGuid().ToString() + Path.GetExtension(fileStream.FileName);
var filePath = Path.Combine(uploadsFolderPath, fileName);

    using (var stream = new FileStream(filePath, FileMode.Create))
    {
        await fileStream.CopyToAsync(stream);
    }

    var photo = new Photo { FileName = fileName };
    vehicle.Photos.Add(photo);
    await unitOfWork.CompleteAsync();
    return Ok(mapper.Map<Photo,PhotoResource>(photo));
}

and the controller with constructor: public class PhotosController : Controller
{
private readonly IHostingEnvironment host;
private readonly IVehicleRepository repository;
private readonly IMapper mapper;
private readonly IUnitOfWork unitOfWork;

    public PhotosController(IHostingEnvironment host, IVehicleRepository repository,IUnitOfWork unitOfWork, IMapper mapper)
    {
        this.mapper = mapper;
        this.repository = repository;
        this.host = host;
}`

error shows on this line:

    var fileName = Guid.NewGuid().ToString() + Path.GetExtension(fileStream.FileName);

which indicates its not getting the "file" object while I am sending an image.jpg with the same key "fileStream".