As you probably heard some time ago Chrome and FF started to redirect sites which use .dev sub domains in URL to https. Issue is described e.g. here: Chrome & Firefox now force .dev domains to HTTPS via preloaded HSTS. Briefly .dev domain is owned by Google and they added HSTS rule for it which forces redirection to https. You may check it in Chrome: open chrome://net-internals#hsts and make query for dev domain:
As you can see there is FORCE_HTTPS rule.
This problem may occur in local dev Sharepoint environments which often use .dev domain. So if you have e.g. site http://intranet.sp.dev and will try to open it in Chrome or Firefox it won’t open it with unclear error:
But if you notice url address bar of the browser you will find that it actually tries to open https://intranet.sp.dev instead of http://intranet.sp.dev and it causes issue. You may try to add https binding to the site using self-signed certificate, but browser will still show error that connection is not secure.
The following solution may be used for avoiding this problem with Sharepoint site. It requires using new site address http://intranet.sp.local for your Sharepoint site instead of http://intranet.sp.dev:
- add intranet.sp.local binding for your Sharepoint site in IIS Manager
- in C:/Windows/System32/drivers/etc/host add
- in Central administration > Alternate access mappings > Add internal url for not used zone: http://intranet.sp.local
After that site can be opened in Chrome and FF using http://intranet.sp.local url.