DataServiceContext.SaveChanges() throws Microsoft.OData.Client.DataServiceRequestException

In my Web App I am trying to update my Album. To do so, I have an OData Web API. I added the OData Web API service to my Web App using this tutorial.

I am having a problem with calling the DataServiceContext.SaveChanges() after I called the DataServiceContext.UpdateObject. This is the error I receive:

I also use DataServiceContext.SaveChanges() in other actions (Get and Delete), and there everything works fine. I just get this error in my Edit action.

Microsoft.OData.Client.DataServiceRequestException
  HResult=0x80131509
  Message=An error occurred while processing this request.
  Source=Microsoft.OData.Client
  StackTrace:
   at Microsoft.OData.Client.SaveResult.HandleResponse()
   at Microsoft.OData.Client.BaseSaveResult.EndRequest()
   at Microsoft.OData.Client.DataServiceContext.SaveChanges(SaveChangesOptions options)
   at biz.dfch.CS.Examples.SampleAspNetCoreWebApp.Controllers.AlbumsController.EditAlbum(Album album) in C:\src\biz.dfch.CS.Examples.SampleAspNetCoreWebApp\src\biz.dfch.CS.Examples.SampleAspNetCoreWebApp\Controllers\AlbumsController.cs:line 64
   at Microsoft.Extensions.Internal.ObjectMethodExecutor.Execute(Object target, Object[] parameters)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.SyncActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeActionMethodAsync()
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterAsync()

Inner Exception 1:
DataServiceClientException: NotFound

This is my Web App Controller:

    public class AlbumsController : Controller
    {
        private Container container;

        public AlbumsController()
        {
            container = new Container(new Uri("https://localhost:44316/odata/"));
        }
        
        public IActionResult EditAlbum(Album album)
        {
            container.AttachTo("Albums", album);
    
            container.UpdateObject(album);
            container.SaveChanges(SaveChangesOptions.ReplaceOnUpdate);    
        
            return RedirectToAction(nameof(Index));
        }
    }

This is my Web API controller:

    public class AlbumsController : ODataController
    {
        [HttpPut]
        public IActionResult UpdateAlbum([FromODataUri] int key,[FromBody] Album album)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }
            if (key != album.Id)
            {
                return BadRequest();
            }
            _context.Update(album);
            try
            {
                _context.SaveChanges();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!AlbumExists(key))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }
            return Updated(album);
        }

        private bool AlbumExists(int key)
        {
            return _context.Albums.Any(a => a.Id == key);
        }
    }

This is my view:

@model biz.dfch.CS.Examples.SampleAspNetCoreWebApi.Models.Album

<div class="row">
    <div class="col-md-4">
        <form asp-action="EditAlbum">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
            <input type="hidden" asp-for="Id" />
            <div class="form-group">
                <label asp-for="Name" class="control-label"></label>
                <input asp-for="Name" class="form-control" />
                <span asp-validation-for="Name" class="text-danger"></span>
            </div>
            <div class="form-group">
                <input type="submit" value="Save" class="btn btn-primary" />
            </div>
        </form>
    </div>
</div>

This is the Album model:

public class Album
{
    public Album()
    {
        Songs = new List<Song>();
    }
    public int Id { get; set; }
    public string Name { get; set; }
    public ICollection<Song> Songs { get; set; }
}

The exception you got points to the problem in the connection (DataServiceClientException: NotFound). It could mean that the service you told it to connect to is not reachable under a given URL.

Are you 100% certain your service is running on https://localhost:44316/odata/? My guess is that it is running on that port, but not under https. Try changing the address to: http://localhost:44316/odata/ and see if that works.