If i fill in remote directory also,still same issue "SFTP channel error".Its something like plug-in problem.
please suggest me correct plug-in.All SFTP and FTP related plug-in is there in jerkin.
Earlier it was working with whatever i provided in attachment.

I attached jenkin.png above in attachment section.i provided the remote directory,still same error.please check and let me know.

Alex pls advise as we r stuck. Is there any webshare we can plan to fix
Or do we need to generate any debug log. Pls confirm how to do so.

We are in very different timezones is my guess, so please don't expect real-time debugging of the issue. It looks like there is an authorization failure, which means the plugin can't login with whatever details you have given it. Adding the remote directory got past the SFTP Channel error, now you have an authentication error.

I can't reproduce this at all. Verify the authentication setup since you are getting an auth fail message.

The message says "Auth fail" right in it in jenkin.png:

jenkins.plugins.publish_over.BapPublisherException: Failed to connect and initialize SSH connection. Message: [Failed to connect session for config [dev]. Message [*Auth fail*]].

There is not currently any debug log to be enabled.

I faced the same error in Ubuntu 18. 

I did the following to get success.

Edit ssh config:
sudo nano /etc/ssh/sshd_config

Change this line:
PasswordAuthentication no
to
PasswordAuthentication yes

Restart daemon:
sudo systemctl restart sshd

For your information, all publish-over-ssh component type JENKINS issues related to the Publish Over SSH plugin have been transferred to Github: https://github.com/jenkinsci/publish-over-ssh-plugin/issues

Here is the direct link to this issue in Github: https://github.com/jenkinsci/publish-over-ssh-plugin/issues/94
And here is the link to a search for related issues: https://github.com/jenkinsci/publish-over-ssh-plugin/issues?q=%22JENKINS-55722%22

(Note: this is an automated bulk comment)

Closing ticket, please use the corresponding Github Issue as linked above.