Program freezes after calling Dispose ()

I am working on an iOS project with C #. The program captures images from a connected webcam and sends it via Socket to iPhone / iPad. All this works great, and I can successfully get my stream on the device.

But when the client disconnects, the webcam must be disconnected, and in this function the program simply freezes. There are no error messages and no exception calls ... just freezes! I believe this is a multi-thread issue, but unfortunately I am not so experienced in C # to find a solution. I hope someone here can lead me on the right path ...

Code:
onImageCaptured Function:

public void OnImageCaptured(Touchless.Vision.Contracts.IFrameSource frameSource, Touchless.Vision.Contracts.Frame frame, double fps)
{
    _latestFrame = frame.Image;
    Console.WriteLine("OnImageCaptured");
    if (isConnected)
    {
        Console.WriteLine("OnImageCaptured - isConnected");
        byteArray = new byte[0];
        MemoryStream stream = new MemoryStream();

        _latestFrame.Save(stream, System.Drawing.Imaging.ImageFormat.Jpeg);
        stream.Close();
        byteArray = stream.ToArray();

        if (byteArray.Length > 0)
        {
            string eof = "<EOF>";
            byte[] eofByte = Encoding.ASCII.GetBytes(eof);
            Console.WriteLine("OnImageCaptured - sendStream");
            this.onDataSend(byteArray);
            this.onDataSend(eofByte);
            stream.Flush();
        }

        System.Diagnostics.Debugger.Log(0, "1", "\nByte Array Length: " + byteArray.Length.ToString());
    }
    pictureBoxDisplay.Invalidate();
}

Defined as in camera class:

public event EventHandler<CameraEventArgs> OnImageCaptured;

And it starts:

OnImageCaptured.Invoke(this, new CameraEventArgs(bitmap, fps));

, - , - , .

, :

public void onDataSend(byte[] data)
{
    clientReady = false;
    try
    {
        socketWorker.Send(data);
    }
    catch (SocketException se)
    {
        isConnected = false;
        Console.WriteLine("Error: Data Write - SocketException");
        Console.WriteLine(se.ErrorCode.ToString());
        thrashOldCamera() // THIS FUNCTION HANGS THE PROGRAM !!
        onDisconnectServer();

        // onDisconnectServer();
    }
    catch (ObjectDisposedException)
    {
        isConnected = false;
        Console.WriteLine("Error: Data Write - ObjectDisposedException");
        // onDisconnectServer();
    }

}

, thrashOldCamera(). ! :

private void thrashOldCamera()
{
    Console.WriteLine("TrashOldCamera");
    // Trash the old camera
    if (_frameSource != null)
    {
        try
        {
            _frameSource.NewFrame -= OnImageCaptured;
            Console.WriteLine("TrashOldCamera - 1");
            _frameSource.Camera.Dispose(); // HERE IT HANGS. IT NEVER GOES PAST HERE !!!
            Console.WriteLine("TrashOldCamera - 2");
            setFrameSource(null);
            Console.WriteLine("TrashOldCamera - 3");
            pictureBoxDisplay.Paint -= new PaintEventHandler(drawLatestImage);
        }
        catch (Exception ex)
        {
            Console.WriteLine("End Trash Camera Ex: " + ex);
        }
    }
    Console.WriteLine("End Trash Camera");
}

_frameSource.Camera.Dispose();. , . , onDataReceive() onImageCapture(). , thrashOldCamera(), .

/ .