In my case the issue was while creating the instance (You can also modify it in the security groups later). My instance was not allowing http/https traffic due to the inbound rules in the security groups. So while creating the instance check the boxes to allow https traffic to the server. If you already have an instance created edit inbound rules to allow traffic for https on port 443. Previously I added custom tcp to allow all IP4's but it did not work.

Hope this helps. Thanks!