Why does Elastic Load Balancing report 'Out of Service'?

Question

I am trying to set up Elastic Load Balancing (ELB) in AWS to split the requests between multiple instances. I have created several images of my webserver based on the same AMI,

Answer 1

I had a similar issue. The problem appears to have been caused due to my using a HTTP health check and also using .htaccess to password protect the site.