How to Fix ‘ERR_SSL_PROTOCOL_ERROR’ on Google Chrome

A quick guide on how to fix Chrome’s ‘This site can’t provide a secure connection’ or ‘ERR_SSL_PROTOCOL_ERROR.’

If Google Chrome is your window to the world of the internet, you must have encountered a “This site can’t provide a secure connection” error or an ERR_SSL_PROTOCOL_ERROR message at least once. The frustrating thing about this error (family of errors, really) is that there’s no easily discernible cause behind it a lot of the time. The SSL errors can pop up on the most popular sites as well as on the least ones. Heck, I’ve gotten one on here, on our website, and I can assure you our SSL/TLS configuration is up to snuff.

Like we just discussed, as far as the reason that Google sometimes says “This site can’t provide a secure connection,” it’s almost impossible to pin it down to a single cause. It can be anything from an issue as trivial as an incorrect system date to far more perplexing server issues – it could be almost anything.

Let’s leave the diagnostic part aside for a moment and focus on what you’re here for – the treatment.

Here’s a quick, troubleshooting guide to fix ERR_SSL_PROTOCOL_ERROR on Google Chrome. If one doesn’t work, try the next one. Sooner or later, you should be able get rid of this issue.

Fix ERR_SSL_PROTOCOL_ERROR by setting the correct Date & Time

Sounds too obvious, doesn’t it? Well, most of the time, the simplest solution to a problem is the correct one. In this case, incorrect date & time settings might be causing trouble for you. So, make sure that your system isn’t lagging behind or running ahead.

Related: Secure Your Domain & Sub-Domains with a RapidSSL Wildcard Certificate.

Why is this a problem? Certificate validity is an extremely important factor in the authentication process, and that means keeping very specific tabs on the time the certificate was signed and when it will expire. If there is an issue with your system’s time and date, it can cause all kinds of problems during authentication. These browsers are designed to err on the side of caution, which is why something as simple as having the wrong time can cause an SSL connection error.

Fix ERR_SSL_PROTOCOL_ERROR by clearing Chrome’s Browsing Data

From one obvious solution to another.

If you already have the correct date & time, it’s time to clear Chrome’s cache and cookies. To do so, press Ctrl + Shift + Delete and erase your browsing data. Even if this hasn’t fixed the “This site can’t provide a secure connection” error, we recommend clearing your browsing data on a regular basis.

Fix ERR_SSL_PROTOCOL_ERROR by clearing your SSL State

If neither of the above works, clearing your SSL State is the next thing you should try. Follow the steps below to do so:

First, go to Customize and control Google Chrome, the three dots you see just below the X (close) button.
Now click on Settings.
Scroll down the page and open the Advanced Settings.
Go to Open proxy settings by scrolling down or searching in the search bar.
A window named ‘Internet Properties’ will open up.
Go to the Content window and click on the Clear SSL State Button.

Fix ERR_SSL_PROTOCOL_ERROR by disabling QUIC Protocol

QUIC (Quick UDP Internet Connections) provides a TLS/SSL equivalent connection to Google’s servers. By default, the QUIC protocol is enabled in Chrome. To disable it, copy chrome://flags/#enable-quic and paste it into the address bar, hit enter. On top of your screen, the Experimental QUIC Protocol would have been set as Default. Disable it and relaunch Chrome.

We don’t necessarily advise this, but it’s been proven to work in some obscure cases so we’re putting it on the list.

Fix ERR_SSL_PROTOCOL_ERROR by checking your Antivirus Settings

Warning: This step isn’t entirely safe as it allows the older, insecure SSL/TLS protocols that some of the websites still use.

You might not know this, but your Antivirus software keeps an eye on the web pages you visit and protects you against any threats they may pose or contain. It does this by checking the SSL/TLS protocol a website uses. Upon finding the protocol to be unsafe and outdated, it prevents you from visiting the site.

There isn’t any one particular way to change the settings for all Antivirus software as the UI and settings differ from one software to another. You’d have to find and see if it’s scanning the SSL protocols. If it does, disable it and see what happens. If the problem persists, revert to the original settings.

Editor’s Note: Generally, the reason you will see an antivirus program cause alarm about an SSL/TLS connection is because the server is attempting to negotiate a connection using a deprecated or vulnerable SSL or TLS version such a SSL 3.0 or TLS 1.0. As we’ve written in similar advice articles, don’t tamper with your antivirus or reduce your TLS version settings to accommodate a website’s bad SSL/TLS configuration. The risks far outweigh the rewards.

Fix ERR_SSL_PROTOCOL_ERROR by Enabling all SSL/TLS Versions – The Last Resort

Warning: This step isn’t entirely safe as it allows the older, insecure SSL/TLS protocols that some of the websites still use.

When you visit an SSL-enabled website, it uses SSL/TLS protocols to communicate with the server. Sometimes, the SSL/TLS version of a website might not be compatible with your Chrome version as Chrome doesn’t permit deprecated SSL/TLS protocols to run by default. Therefore, you’d need to change those SSL/TLS protocol settings. Here’s how you can do it:

Click on the three dots you see in the top-right corner of Chrome and click on Settings.
Now scroll down and go to Advanced Settings.
Find the Proxy settings and open it.
Click on Advanced
Scroll down till the Security section comes up. Now make sure that you have checked all SSL and TLS versions.
Click Apply.
Relaunch your Chrome.

Editor’s Note: Again, consider this suggestion entirely academic. The major browsers have all announced plans to disable support for all previous TLS versions, save TLS 1.2 and the recently-published TLS 1.3. This is being done for security reasons. Don’t enable support for outmoded TLS and SSL versions with known vulnerabilities. No legitimate organization will ask you to compromise your browser’s security settings to interact with its website.

We hope that this guide has helped you fix ERR_SSL_PROTOCOL_ERROR or “This site can’t provide a secure connection” messages on Chrome. And if it doesn’t, share your concerns in the comments section and we’ll try to help you out with it.