Save Image Error: A generic error occurred in GDI+ in ASP.Net

Hi team,

I am getting below error while merging Tiff Image files.

A generic error occurred in GDI+.

Below is my code.

 Class file code

        public string MultiImageName { get; set; }
        public string[] inputTIFFs { get; set; }

        public void Create()
        {
            CreateMTIFF(inputTIFFs, MultiImageName);
        }

        System.Drawing.Imaging.Encoder myEncoder;
        EncoderParameter myEncoderParameter;
        EncoderParameters myEncoderParameters;

        private void CreateMTIFF(string[] stiffs, string mimgname)
        {
            try
            {
                ImageCodecInfo codec = GetEncoderInfo("image/tiff");
                EncoderParameters imgPrms = new EncoderParameters(3);
                Image img = null;

                imgPrms.Param[0] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.ColorDepth, 8L);
                imgPrms.Param[1] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Compression, (long)EncoderValue.CompressionLZW);


                bool firstpage = true;
                foreach (var s in stiffs)
                {
                    Image imgAdd;
                    if (firstpage)
                    {
                        img = Image.FromFile(s);
                        imgPrms.Param[2] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.SaveFlag, (long)EncoderValue.MultiFrame);
                        img.Save(mimgname, codec, imgPrms);
                        firstpage = false;
                    }
                    else
                    {
                        img = Image.FromFile(s);
                        imgPrms.Param[2] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.SaveFlag, (long)EncoderValue.FrameDimensionPage);
                        imgAdd = Image.FromFile(s);
                        img.SaveAdd(imgAdd, imgPrms); // Getting error at this line for second image
                        imgAdd.Dispose();
                    }
                }
                imgPrms.Param[2] = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.SaveFlag, (long)EncoderValue.Flush);

                img.SaveAdd(imgPrms);
                img.Dispose();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }

        public ImageCodecInfo GetEncoderInfo(string mimeType)
        {

            foreach (var ice in ImageCodecInfo.GetImageEncoders())
            {
                if (ice.MimeType.Equals(mimeType))
                    return ice;
            }
            throw new Exception(mimeType + " mime type not found in ImageCodecInfo");
        }

 Aspx codebhind code

string[] arrimgn;
clsMTiff myc = new clsMTiff();
myc = new clsMTiff();
Random r = new Random();
int genRand = r.Next(10, 50);
myc.MultiImageName = Server.MapPath("~/Image/TestImage_Converted_" + genRand.ToString() + ".tif");
arrimgn = new string[3];
arrimgn[0] = Server.MapPath("~/Image/0001.tif");
arrimgn[1] = Server.MapPath("~/Image/0002.tif");
arrimgn[2] = Server.MapPath("~/Image/0003.tif");
myc.inputTIFFs = arrimgn;
myc.Create();