Error in recognizing Vosk C#?

Question

Speech recognition

An error occurred while starting the program for speech recognition. Used the latest version of Vosk and .Net 4.7.1 , downloaded the Russian language pack for Vosk. Below code:

static void Main(string[] args)
        {
            Vosk.Vosk.SetLogLevel(0);

            Model model = new Model("model");
            while (true)
            {
                DemoBytes(model);
                DemoFloats(model);
                DemoSpeaker(model);
            }
        }
        public static void DemoBytes(Model model)
        {
            // Demo byte buffer
            VoskRecognizer rec = new VoskRecognizer(model, 16000.0f);
            rec.SetMaxAlternatives(0);
            rec.SetWords(true);
            using (Stream source = File.OpenRead("test.wav"))
            {
                byte[] buffer = new byte[4096];
                int bytesRead;
                while ((bytesRead = source.Read(buffer, 0, buffer.Length)) > 0)
                {
                    if (rec.AcceptWaveform(buffer, bytesRead))
                    {
                        Console.WriteLine(rec.Result());
                    }
                    else
                    {
                        Console.WriteLine(rec.PartialResult());
                    }
                }
            }
            Console.WriteLine(rec.FinalResult());
        }

        public static void DemoFloats(Model model)
        {
            // Demo float array
            VoskRecognizer rec = new VoskRecognizer(model, 16000.0f);
            using (Stream source = File.OpenRead("test.wav"))
            {
                byte[] buffer = new byte[4096];
                int bytesRead;
                while ((bytesRead = source.Read(buffer, 0, buffer.Length)) > 0)
                {
                    float[] fbuffer = new float[bytesRead / 2];
                    for (int i = 0, n = 0; i < fbuffer.Length; i++, n += 2)
                    {
                        fbuffer[i] = (short)(buffer[n] | buffer[n + 1] << 8);
                    }
                    if (rec.AcceptWaveform(fbuffer, fbuffer.Length))
                    {
                        Console.WriteLine(rec.Result());
                    }
                    else
                    {
                        Console.WriteLine(rec.PartialResult());
                    }
                }
            }
            Console.WriteLine(rec.FinalResult());
        }

        public static void DemoSpeaker(Model model)
        {
            // Output speakers
            SpkModel spkModel = new SpkModel("model-spk");
            VoskRecognizer rec = new VoskRecognizer(model, 16000.0f);
            rec.SetSpkModel(spkModel);

            using (Stream source = File.OpenRead("test.wav"))
            {
                byte[] buffer = new byte[4096];
                int bytesRead;
                while ((bytesRead = source.Read(buffer, 0, buffer.Length)) > 0)
                {
                    if (rec.AcceptWaveform(buffer, bytesRead))
                    {
                        Console.WriteLine(rec.Result());
                    }
                    else
                    {
                        Console.WriteLine(rec.PartialResult());
                    }
                }
            }
            Console.WriteLine(rec.FinalResult());
        }

Mistake