ERROR (ubuntu + chromium)
https://forums.yahoo.net/t5/Errors/NET-ERR-CERTIFICATE-TRANSPARENCY-REQUIRED-on-chromium-53/m-p/141922/highlight/true#M36857
ERR_CERTIFICATE_TRANSPARENCY_REQUIRED
You cannot visit mail.yahoo.com right now because the website uses HSTS.
SOLUTION (no logic here but working at 16 Nov 2016)
https://www.quora.com/How-do-you-fix-the-privacy-error-in-Chrome-Your-connection-is-not-private
On the page displaying this error, click anywhere on the page where the click won't have any action (just to focus the page). Type badidea and voila! You'll be automatically redirected to the destined page. This works sometimes with other sites too.