Successful transfer, but timeout error using FTP

I have been using the WINSCP dll successfully for several integrations that have sFTP sites (the code is written in X++; a .NET 'variation' used in Microsoft Dynamics AX) We have version 5.15.5 (Build 9925). We have one vendor that still has us using an FTP site, but plans to upgrade to sFTP 'soon'. The current code is working fine (not sure exactly what its using) but I thought I would upgrade it to use Winscp and then could just switch the protocol on the session options when the vendor was ready to upgrade us.
The connect works, i can do an EnumerateRemoteFiles to make sure the file I want exists, but when I do a GetFiles it hangs for a minute, gives me a Timeout waiting for WinSCP to respond error but successfully transfers my file! The Putfiles works fine with no timeout or error. Any idea what might be happening? Any help would be greatly appreciated.
Thank you.

Please attach a full session log file showing the problem (using the latest version of WinSCP).


A debug log file (Session.DebugLogPath) might be useful too.

responding again (logged in this time) so I can get notification

I do not see any timeout in the logs. Please make sure you have attached logs for the session that has timeouted.

martin wrote:

I do not see any timeout in the logs. Please make sure you have attached logs for the session that has timeouted.

I'm not sure why, but the timeout error didn't happen once I started writing to the log. But the delay still happens - if you look at the log snippet below (IPs removed) the download gets started, then there is a 30 second delay and its restarted. When there are multiple files, its an extra 30+ seconds for each one. These are tiny files and should take no time to transfer. Maybe you can tell why it fails the first time and then has to restart?

. 2019-12-27 08:12:35.723 Copying "/KAFTEST/BP_KAF_Payment.txt" to local directory started.
. 2019-12-27 08:12:35.723 Binary transfer mode selected.
. 2019-12-27 08:12:35.723 Starting download of /KAFTEST/BP_KAF_Payment.txt
> 2019-12-27 08:13:15.367 TYPE I
< 2019-12-27 08:13:15.398 200 Type set to I.
> 2019-12-27 08:13:15.398 PASV
< 2019-12-27 08:13:15.430 227 Entering Passive Mode (xxx).
> 2019-12-27 08:13:15.430 RETR BP_KAF_Payment.txt
. 2019-12-27 08:13:15.430 Connecting to xxx...
< 2019-12-27 08:13:15.445 150 Opening BINARY mode data connection.
. 2019-12-27 08:13:15.617 Data connection closed
< 2019-12-27 08:13:15.617 226 Transfer complete.

Can you enable a more verbose logging using Session.DebugLogLevel = 1 (or 2)?

Logs attached (I did debug level = 2)

Thanks. Though it unfortunately did not give any more information.

I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

It appears that the zip file only contains winSCP.exe. The problem doesn't happen if I run the client, only when I use the dll from code. Do you have a debug version of the dll?

I have sent you a new package. Let's continue via email.