Please confirm on the above jenkin issue i am completely stuck.

su398397 This is not a support forum. Probably your configuration is wrong either in Jenkins or the target system, but I am not very familiar with this code. I am closing this as not a defect (of course feel free to reopen it if you have additional information that points to this as a regression or similar), but you are more than welcome to write an email to the jenkinsci-users mailing list with a full description of what you are trying to do, what versions of Jenkins, the SSH Slaves Plugin, and the SSH Credentials Plugin you are using, whether this worked previously or just started failing, what operating systems are running on the host/remote machine etc, and maybe someone will be able to help you.

First of all it is not a defect,It is the problem with SSH plugin .
While Connecting From Windows to UNIX machine , i am giving Host name and Username
key details are configured in Unix.
while doing Test Configuration "Failed to get SFTP Channel Error".
please find the attachment above.
Earlier it was working with Hostname and Username,suddenly it is failing.

Jenkin version:2.15
Publish Over SSH:1.20.1

su398397 Repeatedly assigning me to this ticket is pointless, please stop doing it. I am not the person who would be able to help you even if you had provided enough information to do so (I think slide_o_mix is the maintainer based on the plugin site). If you think this is a regression, you need to explain what, if anything, changed on your side (did you update your machines, update the plugin, update Jenkins, etc.)

Does your server support sftp?

Check the logs on the server and see if there is a connection attempt and if there are any errors.

I checked server logs,there is no error.please give proper solutions

It looks like you didn't fill in a remote directory, please try that.

Why there is no update on this issue. Customer is even wanted to go to other tools as Jenkins is not working. Pls advise

I did update on the issue. Please be aware that most of the Jenkins plugins are maintained by volunteers. This means, that we are under no obligation to meet your schedules or anything like that. If you need official support for Jenkins, you are welcome to purchase support from a company like CloudBees. I did update the issue and asked you to try something.

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.