[raaman]

What is an unsupported protocol ? Sometimes when I try to open certain sites, it says 'this site uses an unsupported protocol' and 'this site can't provide a secure connection'. Why does it happen? How to get rid of it?

[gamestoenjoy]

Browsers only support HTTP or HTTPS protocols, so if you go to a site that doesn't support them you will get this message.
There is noting you can do to solve it because the problem is with the site.

[skpeter]

Adding to the answer, for the "unsecure website" issue, most browsers allow you to circumvent it. Which browser are you using? Have you checked if your system date and time is correct?

[germainebull]

How to get rid of it?

I don't think you can get rid of this error message as the issue is not on your part but on the part of the owner of the specific website giving this error message.

[CyberFreak]

Do you use an outdated OS? Reason being is alot of sites that use Cloudflare, use the free plan and that means that the SSL certificate encrypting connections between you and Cloudflare are using a SSL certificate that is not compatible with Windows XP for example so the result is users using outdated OS versions or outdated browsers will encounter SSL errors on some HTTPS sites which will only get worse over time.

I imagine if you visit my ForumCoin faucet, it will give you a similar error.