Read OSM PBF file

[Elgamily]

I'm trying to use the following code to read OSM PBF file:

                string filePath = DownloadFile(textBoxInput.Text);

                using (var fileStream = new FileInfo(@filePath).OpenRead())
                {
                    var source = new PBFOsmStreamSource(fileStream);
                    foreach (var element in source)
                    {
                        //Console.WriteLine(element.ToString());
                    }
                }

but I get an exception as you can see in the attached file.