You are getting a warning message because the information the system has is different than the one it's receiving now. You probably connected to a different machine using the same IP or domain name in the past and that information was saved in your local computer. That information is the one that the computer is using to verify that the cloud instance is the same one you connected before and it's telling you that the information has changed.
If you launched a new instance or configured it with your domain, you will need to remove the information in your system and access the new instance again. If you didn't change anything and continue using the same IP, domain and instance, then you can be running into a man-in-the-middle attack.
Let us know if you have any questions