I would check the configuration file that is used for this login. You'll need the ip address for the target machine. If you don't have it- Go to the TARGET machine, login with delphix/delphix, (unless you changed it, then use the new password) and open up a terminal window. Type in "ifconfig" and get the ip address.
Now on your desktop, open a web browser and type in the ip address:8000
This will open a configuration file. You'll note the engine username and password. Make sure they match what you are putting in. If you want to update it, you can in the section provided, click on Submit Changes and then proceed.
Hope this helps,
Kellyn