Using Debug Build

If we are not able to reproduce the bug you have reported, we will send you a debug build of WinSCP customized to trace down the bug.


Quick Instructions

  • The debug build comes in a ZIP archive.
  • Save the archive to an easily accessible location such as your Windows desktop or your My Documents folder.
  • Extract the archive by opening its context menu (using right-click) and selecting Extract All command.
  • Locate the extracted winscp.exe executable and run it.
  • Reproduce the problem you are having. Please use the most simple scenario for that. Avoid doing any operation with WinSCP that is not strictly necessary to make the problem reproduce.
  • Close WinSCP.
  • Windows File Explorer will open with the trace file selected. Open the context menu of the trace file (using right-click) and select Send to > Compressed (zipped) folder.
  • Email the zipped trace file back to us.
  • Include a regular session log too (unless the problem is GUI related only).
  • Describe the scenario used to reproduce the problem step-by-step for us, including exact times with second precision, exact names of files involved, etc.

Advanced Instructions

  • If the Windows File Explorer does not open with the trace file, locate it manually in the same folder, where you have extracted the winscp.exe executable to. The trace file has a name like winscpXXXXtrace.log.
  • If your scenario involves using, another trace file is created as consoleXXXXtrace.log.
  • If you do not want to send the trace file(s) via email, we can setup a storage with SFTP access for you easily. Let us know.
  • The debug version is slow due to a detailed logging. The slowness may actually prevent the bug from occurring. In such case, let us know, and we will arrange another method for debugging.
  • If you do not have a write access to the executables location, the trace file is not created. On Windows Vista and newer, you might need to run WinSCP with elevated privileges. If you are still not allowed to write to the location, set value of the environment variable WINSCPTRACE to a directory, where you have a write access to. To set an environment variable go to Control Panel > System and Security > System > Advanced System Settings > Advanced > Environment Variables > User variables for … > New. You can also use setx WINSCPTRACE “path” command.
  • The trace file may contain a sensitive information. We do respect your privacy. We will never misuse any information we find in the trace file, nor we will ever share the information with a third party. You can remove anything you do not want to share.
  • In corporate environments, your account profile (including your Windows desktop or your My Documents folder) can be located on a network path. It’s common that a local policy forbids applications started from a network path from accessing an external network/Internet. If that’s the case, and it prevents WinSCP from connecting, please extract the archive to another location on your local drive.


Last modified: by martin