Error when Deploy my application (vaadin8 webapp) to Amazon Web Services

I have a working vaadin-8 web application on Heroku. I want to move it to AWS.

I am following the tutorial given in the link -

As described in this tutorial, I generated the war file and uploaded it. However, when I click on the public link it gives me an error saying :
“The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.”

Does anybody have any idea about this?

I saw in the comments of the tutorial, people have commented about the same problem. I am anyway asking the same question here with the hope of having any discussion.