Thanks for the logs.

This issue has been added to the tracker:
https://winscp.net/tracker/1213

I'm sending you an email with a development version of WinSCP to address you have used to register on this forum.

Sorry about that, thanks for the help

Session.SessionLogPath please, not Session.DebugLogPath.

Also s session log file from GUI session would help too.

So I opened a session with the gui ... works great!!! good work! but when I try it with the .net library (in powershell) I get a 400 error bad request with the same sessionOptions as the gui session.

I've tried a bunch of permutations of the hostname, including the username and the starting directory. But no luck.

Any idea why this would be?

using non-secure webdav, with hostname, password and username set.