Uploading code from C# application to Arduino UNO

Question

A Windows form C# application, it uploads the attendance using Arduino UNO and a finger print sensor attached with it. I am using a library "ArduinoSketchUploader".

Now the problem is when I try to upload the sketch to enroll finger prints while a sketch to match finger prints is already uploaded it gives me an exception.

System.IO.IO.Exception: Unable to establish sync after 20 retires.

But it works fine when I upload a sketch to delete finger prints while a sketch to enroll finger prints is already uploaded and vice versa.

Here is the code:

var uploader = new ArduinoSketchUploader(
    new ArduinoSketchUploaderOptions()
    {
        FileName = "C:\Users\Rizwan\Desktop\delete.ino.hex",
        PortName = sp.PortName,
        ArduinoModel = ArduinoModel.UnoR3
    }
);
uploader.UploadSketch();