550 file unavailable error with FtpWebRequest class file upload. Works fine in FileZilla

Question

I\'m searched and found other questions on this but none have solved my issues. I\'m trying to upload a file via FTP using sample MSDN code. I get the The remote server retu

Answer 1

This answer is for Steen and contains a PowerShell equivalent to the code in http://support.microsoft.com/kb/2134299 below. I don't have a system that has the non-compliant behavior to test against so you'll need to try it yourself.

function SetMethodRequiresCWD() {
    [Type] $requestType = [System.Net.FtpWebRequest]
    [System.Reflection.FieldInfo] $methodInfoField = $requestType.GetField("m_MethodInfo", [System.Reflection.BindingFlags]::NonPublic -bor [System.Reflection.BindingFlags]::Instance)
    [Type] $methodInfoType = $methodInfoField.FieldType


    [System.Reflection.FieldInfo] $knownMethodsField = $methodInfoType.GetField("KnownMethodInfo", [System.Reflection.BindingFlags]::Static -bor [System.Reflection.BindingFlags]::NonPublic)
    [Array] $knownMethodsArray = [Array]$knownMethodsField.GetValue($null);

    [System.Reflection.FieldInfo] $flagsField = $methodInfoType.GetField("Flags", [System.Reflection.BindingFlags]::NonPublic -bor [System.Reflection.BindingFlags]::Instance)

    [int] $MustChangeWorkingDirectoryToPath = 0x100
    ForEach ($knownMethod In $knownMethodsArray) {
        [int] $flags = [int]$flagsField.GetValue($knownMethod)
        $flags = $flags -bor $MustChangeWorkingDirectoryToPath
        $flagsField.SetValue($knownMethod, $flags)
    }
}

Answer 2

It's difficult to tell without detailed information about the error, but it seems most likely that somewhere in your path there's a directory missing. One thing to try if you use any non-standard characters in your FTP file path is to use HttpUtility.UrlPathEncode on it prior to adding it to the Url.

To get detailed troubleshooting information, I add the following inside the configuration element of my application's .config file:

<system.diagnostics>
  <sources>
    <source name="System.Net">
      <listeners>
        <add name="TraceFile"/>
      </listeners>
    </source>
    <source name="System.Net.Sockets" maxdatasize="1024">
      <listeners>
        <add name="TraceFile"/>
      </listeners>
    </source>
  </sources>
  <sharedListeners>
    <add name="TraceFile" type="System.Diagnostics.TextWriterTraceListener" initializeData="System.Net.trace.log" traceOutputOptions="DateTime"/>
  </sharedListeners>
  <switches>
    <add name="System.Net" value="Verbose"/>
    <!--<add name="System.Net.Sockets" value="Verbose"/>-->
  </switches>
  <trace autoflush="true" />
</system.diagnostics>

Also, just for reference, here's the code I use for uploads:

    private static FtpWebRequest CreateFtpWebRequest(string ftpUrl, string userName, string password, bool useSsl, bool allowInvalidCertificate, bool useActiveFtp)
    {
        FtpWebRequest request = (FtpWebRequest)WebRequest.Create(ftpUrl);
        request.Credentials = new NetworkCredential(userName, password);

        if (useSsl)
        {
            request.EnableSsl = true;

            if (allowInvalidCertificate)
            {
                ServicePointManager.ServerCertificateValidationCallback = ServicePointManager_ServerCertificateValidationCallback;
            }
            else
            {
                ServicePointManager.ServerCertificateValidationCallback = null;
            }
        }

        request.UsePassive = !useActiveFtp;

        return request;
    }

    private static void UploadFileToServer(string ftpUrl, string userName, string password, bool useSsl, bool allowInvalidCertificate, bool useActiveFtp, string filePath)
    {
        FtpWebRequest request = CreateFtpWebRequest(ftpUrl, userName, password, useSsl, allowInvalidCertificate, useActiveFtp);

        request.Method = WebRequestMethods.Ftp.UploadFile;

        long bytesReceived = 0;
        long bytesSent = 0;

        using (Stream requestStream = request.GetRequestStream())
        using (FileStream uploadFileStream = File.OpenRead(filePath))
        {
            // Note that this method call requires .NET 4.0 or higher. If using an earlier version it will need to be replaced.
            uploadFileStream.CopyTo(requestStream);
            bytesSent = uploadFileStream.Position;
        }

        using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
        {
            bytesReceived = response.ContentLength;
        }
    }

Answer 3

This did the trick. apparently the CWD command behavior changed in the move from .NET 3.5 to 4.0.

You have to first call the method in this link.

http://support.microsoft.com/kb/2134299

Answer 4

I had this problem just recently. It just popped on code that I had been using for years. It turned out that I had been working with a number of ftp sites and was sending the same files to all these ftp sites. Well, when I went to some ftp sites, I was left at root, but at others, i was immediately put on a subdirectory. Before this recent change I could use request stream and put the file directly on the subdirectly where I was put. As of last week I needed to fully qualify the path.

Hope this helps someone.....