Authentication failed

I want to call WinSCPnet.dll to transfer files with scp protocol. But session.open reports errors when the password is empty, the error message as follows:

WinSCP.SessionRemoteException: Connection has been unexpectedly closed. Server sent command exit status 0.Authentication failed.

When the password is not empty,files are successfully transmitted. Don't you support password empty? Log reference attachment, looking forward to your answer,thanks.

How do you set the empty password? Show us your code.
Also, you should upgrade your version of WinSCP .NET assembly.