I'm getting a strange error in my VB FTP program. It works fine when I download a file from an FTP server, but the second time that I download the same file i get "503 Bad Sequence of Commands".
If I download one file, download 3 other files, and then try to download the first file again, I get the error. If I close the program and open it again, the error is gone when I try to download the file.
Is there some command that I need to send the server to unlock the file or something
"Bad Sequence of Commands" FTP Error
Ken LC
This problem occurs only with a Unix ftp server, not with a Microsoft one. Thanks, Bill....
dziogo2
I fixed it.
If anyone is interested, I had to set the KeepAlive property of my request to false. Even thought the request object was destroyed, it was still keeping the connection to the file open.
2wheels
Ehsan_AIUB
I have the same problem as you had. but when i try to fix it with setting KeeAlive property to false i get an error saying " This operation cannot be performed after the request has been submitted." .I have it like this in my code:
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
request.KeepAlive = false;
and MSDN says
"Changing KeepAlive after calling the GetRequestStream, BeginGetRequestStream, GetResponse, or BeginGetResponse method causes an InvalidOperationException exception."
I don't know where i should put this line. I supposed that it should be right after i don't need the request anymore.Am i wrong
Can you please help me
Thanks
Ravana
I am using a webclient object to download/upload multiple files to/from a remote ftp server. Sometimes it runs just fine and sometimes it gives me error : 503 bad sequence of commands. There is no "keepalive" property of the webclient which I can set to false according to the solution given above. How can I make sure that it will run fine everytime.
private
Exception Upload(WebClient client, string RemoteFile, string LocalFile){
Exception retErr = null; // Get the file name from the local file to name the file on the remote string Filename = Path.GetFileName(LocalFile); // Add the file name that the file will be called on the FTP site. string WebResources = RemoteFile + Filename; try{
// Transfer the file to the FTP site.client.UploadFile(WebResources, LocalFile);
}
catch (Exception ex){
// If any errors occurred report it to the caller.retErr = ex;
}
return retErr;}