c# - FtpWebRequest returns error 550 File unavailable

Question

I have created a small windows forms application to upload the file to one of our client's ftp site. But the problem that I'm having is that when I run this application on my local machine it uploads the file successfully. But if I run this program on our server, I get this error message;

remote server returned an error: (550) File unavailable (eg, file not found, can not access the file), on this line 'objFTPRequest.GetRequestStream();'.

Does anybody know why? Do I need to configure the firewall or something? Here is my code;

FileInfo objFile = new FileInfo(filename);
FtpWebRequest objFTPRequest;

// Create FtpWebRequest object 
objFTPRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/outbox/" + objFile.Name));

// Set Credintials
objFTPRequest.Credentials = new NetworkCredential(ftpUserName, ftpPassword);

// By default KeepAlive is true, where the control connection is 
// not closed after a command is executed.
objFTPRequest.KeepAlive = false;

// Set the data transfer type.
objFTPRequest.UseBinary = true;

// Set content length
objFTPRequest.ContentLength = objFile.Length;

// Set request method
objFTPRequest.Method = WebRequestMethods.Ftp.UploadFile;

// Set buffer size
int intBufferLength = 16 * 1024;
byte[] objBuffer = new byte[intBufferLength];

// Opens a file to read
FileStream objFileStream = objFile.OpenRead();


// Get Stream of the file
Stream objStream = objFTPRequest.GetRequestStream();

int len = 0;

while ((len = objFileStream.Read(objBuffer, 0, intBufferLength)) != 0)
{
    // Write file Content 
    objStream.Write(objBuffer, 0, len);

}

            objStream.Close();
            objFileStream.Close();

Answer 1

This error can be caused because of several reasons like file is not present on server, security permissions on file etc. etc.

First you need to find out the exact cause of error. This can be achieved by using following code-

try
{
        //Your code
}
catch(WebException e)
{
        String status = ((FtpWebResponse)e.Response).StatusDescription;
}

Once you get the exact cause of error, you can go forward to solve it.

Here are some links you can refer

http://forums.asp.net/t/1777881.aspx/1

http://nickstips.wordpress.com/2010/10/25/c-ftp-upload-error-the-remote-server-returned-an-error-550-file-unavailable-e-g-file-not-found-no-access/

http://www.dreamincode.net/forums/topic/76361-file-upload-to-server/

http://forums.asp.net/t/1374306.aspx/1