This issue is particularly relevant for those who set up virtual hosts in their development machines, to work with multiple websites under Apache or other web servers. This issue has been noticed particularly when you load the site in Firefox or Chrome – specially the versions after Dec 2017.
The problem is that if you have a local domain called http://test.dev, firefox immediately converts it to https://test.dev and then fails to load it. Searching on Google will give you several fixes which deal with setting the SSL settings in your Apache configuration and to turn off the auto-fill setting in Firefox about:config. But none of it works , simply because its a domain issue and not a local system issue.
The .dev domain has been purchased by Chrome and they force any request to a domain with .dev extension to use https.
A lot of developers use .dev extension to setup their local websites and this becomes a big pain. So the easy and quick fix is to change the domain extension from .dev to .test or something else. Change it in your server virtualhost settings and etc/hosts file and you are all set.