The SSH connection with the Ubuntu server fails with the error message "Key exchange was not finished, connection is closed.".
The slave is configured to connect and authenticate with username and password.
There is also a warning about a missing ssh known_hosts file (No Known Hosts file was found at C:\Windows\system32\config\systemprofile\.ssh\known_hosts. Please ensure one is created at this path and that Jenkins can read it.), but in windows it is not possible to create a folder with a name starting with a point (.ssh)