Solar-PuTTY requires WinSCP libraries to enable SCP, SFTP, and FTP

Common failure modes implied by “unable to download”

Part 4: The Registry Workaround (For Installed Version Only)

Before diving into fixes, it is crucial to understand the architecture.

He couldn't fix the internet. He couldn't bypass the admin rights. He had to work around the software itself.

SolarWinds acquired Solar Putty from the original developer (Christophe) years ago and has largely left it in maintenance mode. The URL that the portable version calls to download WinSCP libraries is likely a legacy endpoint that no longer exists or has changed.