Error when extracting in WinRAR: "archive is either in unknown format or damaged"

if image size larger than about 300kb,error when extracting in WinRAR: "archive is either in unknown format or damaged".

Code:

MemoryStream memoryStream = new MemoryStream();

using (ZipFile zip = ZipFile.Create(memoryStream))

{

zip.BeginUpdate();

string filePath = @"D:/CARTON-220001.jpg";//446kb

using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read))

{

int length = (int)fs.Length;

                byte[ data = new byte[length];

                fs.Position = 0;

                fs.Read(data, 0, length);

                MemoryStream docMS = new MemoryStream();

                docMS.Write(data, 0, length);

                StreamDataSource docSDS = new StreamDataSource(docMS);

                docMS.Close();

                zip.Add(docSDS, "CARTON-220001.jpg");

         }

         zip.CommitUpdate();

}

FileStream file = new FileStream("x.zip", FileMode.Create);

file.Write(memoryStream.GetBuffer(), 0, (memoryStream.GetBuffer()).GetLength(0));

file.Close();