First, try to troubleshoot your issue yourself.

When posting your request for support or reporting bug, please include as much of the following information as you know. If you do not know some of these information or if you suppose that some are irrelevant for the issue, please mention that as well.

• Version of WinSCP you are using (you should be using the latest version if possible).
• If the problem started to occur after upgrade, mention the last version of WinSCP which was working for you1).
• Version of Microsoft Windows you are running WinSCP on.
• Transfer protocol (SFTP, FTP or SCP). For SFTP include also the protocol version (if you ever succeeded to login). You can see it in Server/protocol information dialog as "SFTP-X".
• Mention if you use GUI or scripting/automation. If you use GUI, specify interface style you are using (Commander or Explorer).
• If you experience an error, include full error message. You may use Ctrl+C to copy the message, then paste it (Ctrl+V) to the post. Also check list of common error messages.
• Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.). If you are not able to reproduce the problem with the steps, it is probably not worth to report it as I will not be able to reproduce it (and solve) too.
• Software of the server you are connecting too (if you can get this information).
• For scripting/automation-related issues, include your full script, command-line you use to run WinSCP, and output you see on WinSCP console.
• If your problems relates to interaction with remote server, please post a full log file showing the problem. To generate log file, enable logging, log in to your server and do the operation and only the operation that causes the error. For posting extensive logs you may use pastebin or similar application. Note that passwords and passphrases are not stored in the log. You may want to remove other data you consider sensitive though, such as host names, IP addresses, account names or file names (unless they are relevant to the problem). If you do not want to post the log publicly, you may email it to me. Though still you need to first post on the support forum, just mention that you are doing to email the log. Otherwise your email will be ignored. Please include link back to your post in your email. You will find my address (if you log in) in my forum profile.

Register on the forum before you post. I may be able to deal with your issue only after some time, so I would appreciate if I have a contact to you.