If you are trying to run WordPress on AWS and are getting messages about loopback connection failed or cURL error 28: connection timed out then that means that WordPress can’t do a loopback to itself. On AWS, the problem is most likely due to the public/private IP address. The solution to this problem is that you need to put your domain name into your /etc/hosts file with your domain name set to 127.0.0.1. What is going on is WordPress is doing a DNS query to find your servers public DNS address. Then it is trying to connect to it by sending it out the gateway router and it is getting messed up. By setting your domain name in /etc/hosts, it tells it just to connect to itself and the loopback request goes through.