How do I solve the problem "an error occured: exception from HRESULT: 0xfffffff8"

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C#

Visual-Studio

error-handling

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I am using visual studio and trying to verify a fingerprint template and to generate the record that corresponds to the fingerprint i scanned using uareu fingerprint reader. The entire verification code is below. Please help me find this error as i am just getting excited with c# programming

using DPFP;
using DPFP.Capture;
using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Forms;
using static Mysqlx.Notice.Warning.Types;
using System.IO;


namespace ExaminationAuthentication
{
    public partial class verificationForm : Form, DPFP.Capture.EventHandler
    {

        private DPFP.Capture.Capture Capturer;
        private DPFP.Verification.Verification Verificator;

        public verificationForm()
        {
            InitializeComponent();
            Verificator = new DPFP.Verification.Verification();
        }

        public void OnComplete(object Capture, string ReaderSerialNumber, DPFP.Sample Sample)
        {
            this.Invoke(new Action(() =>
            {
                MakeReport("The fingerprint sample was captured. Checking against the database...");
                try
                {
                    Process(Sample);
                }
                catch (Exception ex)
                {
                    MessageBox.Show($"Error during processing: {ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }));
        }

        public void OnFingerGone(object Capture, string ReaderSerialNumber)
        {
            SetStatus("The finger was removed from the fingerprint reader.");
        }

        public void OnFingerTouch(object Capture, string ReaderSerialNumber)
        {
            SetStatus("The fingerprint reader was touched.");
        }

        public void OnReaderConnect(object Capture, string ReaderSerialNumber)
        {
            SetStatus("The fingerprint reader was connected.");
        }

        public void OnReaderDisconnect(object Capture, string ReaderSerialNumber)
        {
            SetStatus("The fingerprint reader was disconnected.");
        }

        public void OnSampleQuality(object Capture, string ReaderSerialNumber, CaptureFeedback CaptureFeedback)
        {
            if (CaptureFeedback == DPFP.Capture.CaptureFeedback.Good)
                SetStatus("The quality of the fingerprint sample is good.");
            else
                SetStatus("The quality of the fingerprint sample is poor.");
        }


        protected void SetStatus(string message)
        {
            this.Invoke(new Action(delegate ()
            {
                StatusLabel.Text = message;
            }));
        }

        protected void MakeReport(string message)
        {
            this.Invoke(new Action(delegate ()
            {
                StatusText.AppendText(message + "\r\n");
            }));
        }
      

        private void verificationForm_Load(object sender, EventArgs e)
        {
            try
            {
                Capturer = new DPFP.Capture.Capture();
                if (Capturer != null)
                {
                    Capturer.EventHandler = this;
                    MakeReport("Press start capture to start scanning for authentication.");
                }
                else
                {
                    MakeReport("Cannot initiate capture operation.");
                }
            }
            catch
            {
                MessageBox.Show("Can't initiate Capture Operation!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }


        protected virtual void Process(DPFP.Sample Sample)
        {
            this.Invoke(new Action(() =>
            {
                Bitmap fingerprint = ConvertSampleToBitmap(Sample);
                DrawPicture(fingerprint);

                // Extract features from the fingerprint sample
                DPFP.FeatureSet features = ExtractFeatures(Sample, DPFP.Processing.DataPurpose.Verification);

                if (features != null)
                {
                    VerifyFingerprint(features);
                }
                else
                {
                    MessageBox.Show("The fingerprint quality is poor. Please try again.", "Quality Error", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                }
            }));
        }


        private DPFP.FeatureSet ExtractFeatures(DPFP.Sample Sample, DPFP.Processing.DataPurpose Purpose)
        {
            DPFP.Processing.FeatureExtraction extractor = new DPFP.Processing.FeatureExtraction();
            DPFP.Capture.CaptureFeedback feedback = DPFP.Capture.CaptureFeedback.None;
            DPFP.FeatureSet features = new DPFP.FeatureSet();

            try
            {
                extractor.CreateFeatureSet(Sample, Purpose, ref feedback, ref features);
                if (feedback == DPFP.Capture.CaptureFeedback.Good)
                {
                    return features;
                }
                else
                {
                    MakeReport("The fingerprint sample quality is not sufficient.");
                    return null;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Error extracting features: {ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return null;
            }
        }


        private void VerifyFingerprint(DPFP.FeatureSet features)
        {
            string connectionString = "server=localhost;user=root;database=ivs;password=";

            using (MySqlConnection connection = new MySqlConnection(connectionString))
            {
                string query = "SELECT * FROM students";

                using (MySqlCommand cmd = new MySqlCommand(query, connection))
                {
                    try
                    {
                        connection.Open();
                        using (MySqlDataReader reader = cmd.ExecuteReader())
                        {
                            while (reader.Read())
                            {
                                byte[] storedFingerprint = (byte[])reader["fingerprint"];
                                DPFP.Template template = new DPFP.Template();
                                template.DeSerialize(storedFingerprint);

                                DPFP.Verification.Verification.Result result = new DPFP.Verification.Verification.Result();
                                Verificator.Verify(features, template, ref result);

                                if (result.Verified)
                                {
                                    MessageBox.Show("Fingerprint match found! Retrieving user data...");

                                    // Display the user's details
                                    DisplayUserData(reader);
                                    return;
                                }
                            }
                        }

                        MessageBox.Show("No matching fingerprint found in the database.", "Authentication Failed", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show($"An error occurred: {ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                }
            }
        }


        private void DisplayUserData(MySqlDataReader reader)
        {
            // Assuming you have text boxes and other controls named accordingly on your form
            txtSurname.Text = reader["surname"].ToString();
            txtOthernames.Text = reader["othernames"].ToString();
            txtSex.Text = reader["sex"].ToString();
            txtDOB.Value = Convert.ToDateTime(reader["dob"]); // Assuming txtDOB is a DateTimePicker
            txtPhoneNumber.Text = reader["phoneNumber"].ToString();
            txtEmailAddress.Text = reader["emailAddress"].ToString();
            txtResidentialAddress.Text = reader["residentialAddress"].ToString();
            txtStateOfOrigin.Text = reader["stateOfOrigin"].ToString();
            txtLocalGovernmentArea.Text = reader["localGovernmentArea"].ToString();
            txtMatricNumber.Text = reader["matricNumber"].ToString();
            txtLevel.Text = reader["level"].ToString();
            txtDepartment.Text = reader["department"].ToString();
            txtSchool.Text = reader["school"].ToString();

            // Convert the timestamp to a DateTime format and display it
            txtTimestamp.Text = Convert.ToDateTime(reader["timestamp"]).ToString("yyyy-MM-dd HH:mm:ss");

            // Convert the byte array from the database back into an Image for the passport
            byte[] passportData = (byte[])reader["passport"];
            if (passportData != null && passportData.Length > 0)
            {
                using (MemoryStream ms = new MemoryStream(passportData))
                {
                    pbPassport.Image = Image.FromStream(ms); // Display the passport image in the PictureBox
                }
            }

            // Display a success message
            MessageBox.Show("User data retrieved successfully and populated in the form.", "Data Retrieved", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }


        protected Bitmap ConvertSampleToBitmap(DPFP.Sample Sample)
        {
            DPFP.Capture.SampleConversion Convertor = new DPFP.Capture.SampleConversion();
            Bitmap bitmap = null;
            try
            {
                Convertor.ConvertToPicture(Sample, ref bitmap);
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Error converting sample to bitmap: {ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            return bitmap;
        }

        private void DrawPicture(Bitmap bitmap)
        {
            pbFingerprint.Image = new Bitmap(bitmap, pbFingerprint.Size);
        }

        private byte[] SampleToByteArray(DPFP.Sample sample)
        {
            DPFP.Capture.SampleConversion converter = new DPFP.Capture.SampleConversion();
            Bitmap bitmap = null;
            converter.ConvertToPicture(sample, ref bitmap);

            using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
            {
                bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
                return ms.ToArray();
            }
        }

        private void verificationForm_FormClosed(object sender, FormClosedEventArgs e)
        {
           
        }

        private void btnStopCapture_Click(object sender, EventArgs e)
        {
            if (Capturer != null)
            {
                try
                {
                    Capturer.StopCapture();
                    MakeReport("Stopped scanning the fingerprint.");
                }
                catch
                {
                    MakeReport("Can't terminate Capture.");
                }
            }
        }

        private void btnCaptureFingerprint_Click(object sender, EventArgs e)
        {
            if (Capturer != null)
            {
                try
                {
                    Capturer.StartCapture();
                    MakeReport("Using the fingerprint reader, scan your fingerprint.");
                }
                catch
                {
                    MakeReport("Can't initiate Capture.");
                }
            }
        }
    }
}

Thanks you for your help

What I have tried:

I dont know much about C# programming so please help me as you can.
Once again, this is the problem I am facing:

"An error occured: Exception from HRESULT: 0xFFFFFFF8"