Undefined object reference for an object instance when calling dll class

Question

I am trying to call a function of a class that is in a DLL. But the error "Undefined object reference to an instance of an object" is showing, I don’t understand why because the IDE shows no error.

What am I doing wrong?

Follows code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Threading;
using System.Runtime.InteropServices;

namespace player
{
    public partial class frmPrincipal : Form
    {

        System.Media.SoundPlayer soundPlayer;
        RSPOggPlayer279a.RSPOggPlayClass playerRSP;

        public frmPrincipal()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void tocar()
        {

            playerRSP.UseEncryption(true, "988d90fsdhfnu943yrtherjh0qw9rifj");
            //playerRSP.PlayFile("C:\Users\kleber.santos\7b.ogg");





            //byte[] buffer = File.ReadAllBytes(@"C:\Users\kleber.santos\Downloads\africa-toto.wav");
            //System.IO.File.Delete(@"C:\Users\kleber.santos\Downloads\africa-toto.wav");
            //var memoryStream = new MemoryStream(buffer, true);
            //soundPlayer = new System.Media.SoundPlayer(memoryStream);
            //Play();
        }

        public void Play()
        {
            soundPlayer.Play();
        }

        private void BtnPlay_Click(object sender, EventArgs e)
        {
            tocar();
        }

        private void BtnVolume_Click(object sender, EventArgs e)
        {

        }
    }
}

Answer 1

Kleber, This message is typical for non instantiated objects. Checks the instance of the Rspoggplayer279a.RSPOggPlayClassobject. I believe it’s a class created by you.