Hi Irina,

You need to move the current position in the stream to its begin position (instead of the end) and it should be OK:

   var memoryStream = new MemoryStream();
    nChartControl1.ImageExporter.SaveToStream(memoryStream, new NSize(500, 500), NResolution.ScreenResolution, new NEmfImageFormat());

    memoryStream.Seek(0, SeekOrigin.Begin);
    var image = Image.FromStream(memoryStream);

Best Regards,
Nevron Support Team