Naudio unvalid operation exception unhandeled - wpf

Question

I am using Naudio in WPF for the first time.It keeps giving an exception "InvalidOperationException was unhandled".Buffer Bull.I don't know how to handle it. So far there is no error that is being shown by the debugger.
The Lines that are throwing the exception
waveFile.Write(e.Buffer, 0, e.BytesRecorded); and
sourceStream.StartRecording();
public partial class voiceNote : Window
{
public voiceNote()
{
InitializeComponent();
}
public NAudio.Wave.WaveIn waveSource = null;
public NAudio.Wave.WaveFileWriter waveFile = null;
private void resources_Click(object sender, RoutedEventArgs e)
{
List<NAudio.Wave.WaveInCapabilities> sources = new List<NAudio.Wave.WaveInCapabilities>();
for (int i = 0; i < NAudio.Wave.WaveIn.DeviceCount; i++)
{
sources.Add(NAudio.Wave.WaveIn.GetCapabilities(i));
}
//to make sure refreshed
devicesList.Items.Clear();
foreach (var source in sources)
{
//ListViewItem item;
devicesList.Items.Add(source.ProductName);
//= new ListViewItem(source.ProductName.ToString);
//item.SubItem.Add(new ListViewItem.ListViewSubItem(item, source.Channels, ToString()));
//sourceList.Items.Add(item);
}
}
//to get input....Sound Source
NAudio.Wave.WaveIn sourceStream = null;
//To sync the source of input and input audio
NAudio.Wave.DirectSoundOut waveOut = null;
// To write wve file
NAudio.Wave.WaveFileWriter waveWriter = null;
private void startRecording_Click(object sender, RoutedEventArgs e)
{
// if (devicesList.SelectedItem.Count = 0) return;
int devicenumber = devicesList.SelectedIndex;
// int devicenumber = devicesList.SelectedItems[0].index;
sourceStream = new NAudio.Wave.WaveIn();
sourceStream.DeviceNumber = devicenumber;
sourceStream.WaveFormat = new NAudio.Wave.WaveFormat(44100, NAudio.Wave.WaveIn.GetCapabilities(devicenumber).Channels);
NAudio.Wave.WaveInProvider waveIn = new NAudio.Wave.WaveInProvider(sourceStream);
//*****************************
//waveOut = new NAudio.Wave.DirectSoundOut();
//waveOut.Init(waveIn);
//sourceStream.StartRecording();
//waveOut.Play();
sourceStream.DataAvailable += new EventHandler<NAudio.Wave.WaveInEventArgs>(sourceStream_DataAvailable);
// waveWriter = new NAudio.Wave.WaveFileWriter(sav.FileName, sourceStream.WaveFormat);
sourceStream.StartRecording();
}
private void sourceStream_DataAvailable(object sender, NAudio.Wave.WaveInEventArgs e)
{
// //data is byte array, buffer, count
// waveWriter.WriteData(e.Buffer, 0, e.BytesRecorded);
// waveWriter.Flush(); //to write on disk.... so data is not held up on the ram
}
private void stopandsave_Click(object sender, RoutedEventArgs e)
{
if (waveOut != null)
{
waveOut.Stop();
waveOut.Dispose();
waveOut = null;
}
//Stop Recording
if (sourceStream != null)
{
sourceStream.StartRecording();
sourceStream.Dispose();
sourceStream = null;
}
if (waveWriter != null)
{
waveWriter.Dispose();
waveWriter = null;
}
}
}