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I got exception while upload file to ftp server. I am doing following code and get The type initializer for 'System.Net.FtpWebRequest' threw an exception.

private FtpWebRequest ftpRequest = null;
            private Stream ftpStream = null;
            private int bufferSize = 2048;

protected void btnSubmit_Click(object sender, EventArgs e)
            byte[] byteBuffer = new byte[bufferSize];
            byte[] Data = fileArray.FileBytes;
           TransferFile(fileArray.PostedFile.FileName, Data));

public string TransferFile(string filename, byte[] fileContent)

            string strMsg = string.Empty;

                /* Create an FTP Request */
                String uploadUrl = String.Format("{0}/{1}/{2}", "ftp://address", "foldername", filename);
                ftpRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri(uploadUrl));
                /* Log in to the FTP Server with the User Name and Password Provided */
                ftpRequest.Credentials = new NetworkCredential("Username", "Password");
                /* When in doubt, use these options */
                ftpRequest.UseBinary = true;
                ftpRequest.UsePassive = true;
                ftpRequest.KeepAlive = true;
                /* Specify the Type of FTP Request */
                ftpRequest.Method = WebRequestMethods.Ftp.UploadFile;
                ftpStream = ftpRequest.GetRequestStream();                

                /* Upload the File by Sending the Buffered Data Until the Transfer is Complete */
                    ftpRequest.ContentLength = fileContent.Length;

                    Stream requestStream = ftpRequest.GetRequestStream();
                    requestStream.Write(fileContent, 0, fileContent.Length);
                    FtpWebResponse response = (FtpWebResponse)ftpRequest.GetResponse();
                    strMsg = "File Upload Status: " + response.ToString();

                catch (Exception ex) { Console.WriteLine(ex.ToString()); }
                /* Resource Cleanup */
                ftpRequest = null;
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
            return strMsg;


Please suggest if I do wrong.
Sergey Alexandrovich Kryukov 23-May-13 9:07am    
No, thank you. First, please provide comprehensive exception information.
rajesh@1989 23-May-13 9:15am    
This error has vanished after I restart me system but found new error:

System.Net.WebException was caught
Message=The remote server returned an error: (550) File unavailable (e.g., file not found, no access).
at System.Net.FtpWebRequest.SyncRequestCallback(Object obj)
at System.Net.FtpWebRequest.RequestCallback(Object obj)
at System.Net.CommandStream.Dispose(Boolean disposing)
at System.IO.Stream.Close()
at System.IO.Stream.Dispose()
at System.Net.ConnectionPool.Destroy(PooledStream pooledStream)
at System.Net.ConnectionPool.PutConnection(PooledStream pooledStream, Object owningObject, Int32 creationTimeout, Boolean canReuse)
at System.Net.FtpWebRequest.FinishRequestStage(RequestStage stage)
at System.Net.FtpWebRequest.GetRequestStream()
at BizConnectPro_BAL_DAL.FileUpload.TransferFile(String filename, Byte[] fileContent) in E:\BizConnect-Pro_BAL_DAL Project\BizConnectPro_BAL_DAL\BizConnectPro_BAL_DAL\FileUpload.aspx.cs:line 50

Why this error occured while I already pass filecontent to it.
I guess the upload Url is a problem.
Can you debug and tell what is the exact value coming for uploadUrl ?
Sergey Alexandrovich Kryukov 23-May-13 9:22am    
It could be...
rajesh@1989 23-May-13 9:27am    
Why? I realy wants to know file uploading method to ftp. I am newbie.
Please explain where I do wrong?

1 solution

You need to increase the FtpWebRequest.Timeout Property [^].

Refer - The underlying connection was closed: An unexpected error occurred on a receive[^].
Just want to strengthen ScottE's diagnosis, and be more specific. Timeout is most likely the issue.

Either .Net implementation of FtpWebRequest is erroneous or the MSDN document has a typo, the default value of FtpWebRequest.Timeout is not -1 (Infinite). It is 100000 (100 seconds).

In addition there is another timeout issue. A few tests have shown that responseStream always has a timeout value of 300000 (300 seconds). I do not how this value is assigned. Anyways, this value needs to be modified to accommodate large files.

In summary, the solution is to set FtpWebRequest.Timeout and Stream.Timeout to a sufficiently large value
Share this answer
rajesh@1989 24-May-13 3:03am    
Hi Tadit,
Thank you again.

I know as I am accept your solution there is no right to ask a question to you in this thread. But I am facing critical problem that How to make webservice that uses TransferFile() method by multipart form data?.
I have write following code for it:
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public void TransferFile()

HttpContext postedContext = HttpContext.Current;
HttpFileCollection Request = postedContext.Request.Files;
foreach (HttpPostedFile item in Request)
string filename = item.FileName;

byte[] fileBytes = new byte[item.ContentLength];
item.InputStream.Read(fileBytes, 0, item.ContentLength);
objFileTransfer.TransferFile(filename, fileBytes);

//objFileTransfer.TransferFile(filename, fileBytes);
retJSON = js.Serialize(new { Result = objFileTransfer.TransferFile(filename, fileBytes) });
// fileBytes now contains the content of the file
// filename contains the name of the file
Is this webservice get multipart form data?
When an iPhone developer consume this api they got response like:
Problem uploading file: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index
rajesh@1989 26-May-13 9:13am    
hi Tadit,

Can you please reply for above ?
Hi Rajesh,

I saw your last comment when you added that, but I could not check this as I am at home on weekends. And I don't have my Laptop with me.
So, when I will be in office on Monday, definitely I will check this.

In the mean time, I would suggest you to create a new thread, so that others can help you.

Tell me one thing - Can you debug this service and check where exactly it is throwing exception ?
rajesh@1989 27-May-13 15:46pm    
Hi Tadit,

How can I debug my web service?
Here my question that is this web service will accept multipart form-data?
I have created a new thread for this

when I phone developer consume this service they get 'invalid request' by posting data as multipart form-data with boundary.
I have answered you in that question. Please check.

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