Do you use Google Chrome regularly? If so, you might have seen the ERRSSLPROTOCOL_ERROR before. This is a Secure Sockets Layer (SSL) error caused by Chrome’s failure to connect to a site securely, due to a problem with the client’s browser or the site’s SSL certificate.

However, while the ERR_SSL_PROTOCOL_ERROR’s primary cause can be hard to pinpoint in many cases, you can nevertheless repair it in pretty straightforward ways.

In this guide to fixing the ERR_SSL_PROTOCOL_ERROR, we’ll explore the various causes for the error, multiple techniques for repairing it, and how different web browsers present the error.


The ERR_SSL_PROTOCOL_ERROR is a network communication protocol error that appears when a website has an issue with its SSL certificate or a browser can’t connect to a site with SSL protection. It may also be down to improper SSH installation or a network problem.

Reasons Why the ERR_SSL_PROTOCOL_ERROR Occurs?

When you see a website with an SSL credential, you can trust that it’s a legitimate site, which is why it’s such an important part of the HTTPS protocol. Your browser requests a site’s SSL certificate when you visit it to make sure the connection is secure.

When establishing the connection to an SSL-protected website, a browser delivers a client authentication certificate to the server hosting the website (a process called the “TLS handshake”).

Once this authentication is done, data is transmitted and the browser is able to present the relevant page. Failing that, though, the browser will present you with a certain error message to represent the specific problem. Google Chrome users will see the ERR_SSL_PROTOCOL_ERROR message.

However, identifying the cause of the error can be tough. It could be the result of a website error or something on your side.

For the latter, the error may be due to the QUIC protocol, SSL caches that are out of date, or browser extensions that need to be updated. Additionally, the secure connection may be prevented by antivirus software or Windows Defender Firewall.

If you run into the ERR_SSL_PROTOCOL_ERROR when trying to visit a site, the following steps are worth a try:

  • Deactivate your antivirus or firewall, just for long enough to see if that makes a difference.
  • Turn off any browser extensions that are out of date or otherwise tricky.
  • Make sure your system date and time are correct.
  • Switch off QUIC protocol.
  • Clear your browser’s cache.

None of these fix the problem? Well, then it’s likely the website is to blame for the ERR_SSLPROTOCOL_ERROR. To discover whether the site is down for just you or all users, take advantage of website checker tools.

For problems on the website’s side, one common cause is SSL misconfiguration (such as when a HTTPS is forced with no valid SSL certificate in place). On the other hand, the issue may still be caused when HTTPS is not forced on a site with an SSL certificate.

Fixing ERR_SSL_PROTOCOL_ERROR: 3 Simple Steps

As identifying the exact cause for an ERRSSL_PROTOCOL_ERROR can be tough, there are three common steps that website visitors and owners can take to fix it. These include forcing HTTPS, wiping a web browser’s cache and SSL state, and confirming that SSL has been installed. If you try any of these without success, see if either of the others works.

Confirm SSL Installation

If you force HTTPS but don’t have SSL installed, your site will be inaccessible and will present the ERR_SSL_PROTOCOL_ERROR. This occurs when a website lacks the certificate needed to allow HTTPS connections.

Depending on the hosting service you use for your website, you should be able to determine if SSL is installed. It may be as simple as opening your hosting provider’s control panel and checking the SSL status. You can use various tools for diagnosing problems with SSL installation too.

If you don’t have an SSL certificate installed and active, you’ll need to get one before you activate HTTPS. A wide range of companies provide different SSLs, and picking just one can be difficult. However, we’ve put together a few tips below to help you buy the most suitable certificate for you:

  • Only buy from a valid provider: You should only purchase an SSL certificate from a legitimate company to make sure that it’s trustworthy. Check out reviews from other customers before committing.
  • Research warranty information and customer care: Buy your SSL certificate from a company with 24/7 support available and warranties. As a result, you’ll be able to address issues that may arise or get your money back if necessary.
  • Think about your budget carefully: The cost of SSL certificates can differ widely. However, you can pick up a free one from Let’s Encrypt (a nonprofit organization) instead. While you can get a free certificate from Let’s Encrypt, you’ll need to have it renewed every 90 days.
  • Understand what you need it for: SSL is capable of supporting a variety of domains, depending on which type you have. A multi-domain certificate offers protection for several domains, for instance, and a wildcard SSL is helpful for protecting a main domain as well as all of its subdomains.

How do you buy an SSL certificate? The specifics vary depending on which provider you use, though it tends to be similar overall:

  • Create your Certificate Signing Request (CSR) — this is the encoded data for your site’s domain name, public key, and contacts.
  • Buy the right SSL certificate for your site and needs.
  • Deliver your Certificate Signing Request to a certificate issuer (such as the Certification Authority).
  • Once your domain validation has been completed, install your website’s SSL certificate.

Forcing HTTPS on Your Domain

Have you installed your SSL certificate? Great — your site will now be available in two protocols: HTTP and HTTPS. However, it will use HTTP as standard unless you force it to run HTTPS.

You should check if HTTPS is forced on your site if the above step doesn’t fix the ERR_SSL_PROTOCOL_ERROR problem. Changing to HTTPS from HTTP can create issues for your site, and even make it inaccessible. That’s why you should make a backup before you initiate any further changes, just in case things don’t go to plan.

The steps required to force HTTPS on your site will differ depending on your hosting provider and the control panel used. But here are two options:

  • For websites created with WordPress, use that platform to install an SSL certificate and force HTTPS.
  • Force HTTPS by modifying your .htaccess file code (you’ll find this in the root directory for your WordPress website).

However, you should check that the DNS settings on your site are propagated completely before you make the SSL certificate. WhatsMyDNS is just one checker tool available to help with propagation tracking. The process is typically complete within 24 hours.

If you install your SSL certificate before full DNS propagation is complete, that could trigger the ERR_SSL_PROTOCOL_ERROR problem. That’s because the certification will be linked with a domain name that’s incorrect. If that happens, you should uninstall the SSL and go through the troubleshooting steps again.

Empty the Cache in Your Web Browser

If the problem causing the ERR_SSL_PROTOCOL_ERROR is on the website’s side, completing the above steps should have fixed it. But if you see the error again, the cause is most likely your web browser. This is where its cache comes in.

A browser stores data on websites you visit (e.g. texts, pictures, and SSL) as a cache. The browser then retrieves these from the cache the next time you go back to that same website, instead of going to the server the website is on. That leads to faster load times and a more convenient user experience.

Still, while there’s a clear benefit to a browser’s cache, it can create issues too. If a site has undergone any significant modifications since your previous visit, the browser might be unable to show it until it has the new information it needs.

However, if you clear your web browser’s cache, the cache will be forcibly renewed with the updated information it requires. That could fix a number of problems affecting your browser, most importantly SSL errors.

The process for clearing your cache will differ slightly depending on which browser you use, though it tends to be similar. If you use Chrome, follow these steps:

  • In Chrome, tap the icon made up of three tiny dots next to the address bar.
  • A drop-down menu will appear. Here, tap ‘More tools’ then ‘Clear browsing data’.
  • Use the ‘Time range’ drop-down menu to specify how far back you want to clear the cache (e.g. ‘Last hour’). To make sure all of your browser’s caches are wiped effectively, select ‘All time’.
  • Determine the type of website data to delete. If you want to focus on caches only, check the ‘Cached images and files’ box. However, you can wipe the Browser history’ as well as ‘Cookies and other site data’.
  • When you’re ready, tap the ‘Clear data’ button in the bottom-right corner.
  • Restart Chrome.

Do you use Windows? Use ‘Ctrl+Shift+Delete’ to open the menu for deleting your browser data. You can use this for the majority of browsers, such as Firefox, Microsoft Edge, Chrome, and Opera. ‘Command+Shift+Delete’ does the same for macOS devices.

However, here’s a key point to bear in mind for after you clear your cache: websites will load more slowly, and removing the browsing data will log you out of the majority of sites.

As with Chrome, you can access the clear cache option through the settings menu in most other browsers. Many browsers also let you choose the type of browsing data and deletion time frame too (though Safari doesn’t at the time of writing).

Additionally, wiping a browser’s SSL state is another technique for fixing the ERR_SSL_PROTOCOL_ERROR. SSL caches are stored by browsers for similar reasons. However, if a site has an updated certificate, SSL caches can create SSL connection problems as the cached certificate doesn’t align with the latest one.

The steps needed to clear your browser’s SSL state can differ by browser and OS. But if you’re using Google Chrome on a Windows system, follow these steps:

  • Launch your browser and tap the icon featuring three tiny dots. Then choose ‘Settings’.
  • Scroll down to ‘System’ on the left-hand sidebar. Click ‘Open proxy settings’.
  • ‘Internet Properties’ will pop up on your screen. Tap on the ‘Content’ tab followed by ‘Clear SSL state’.
  • Click ‘OK’ to confirm the process.

The process is slightly different for older versions of Chrome. Open the ‘Settings’ menu, click on ‘Advanced settings’, then find the ‘Open proxy settings’ button (under ‘Network’).

Alternatively, in the latest Windows systems, type ‘Internet properties’ then press ‘Enter’.

While on Chrome, you can also wipe the SSL state with ‘Manage certificates’.

  • Click on the three-dots icon in Chrome, followed by ‘Settings’.
  • Select ‘Privacy and security’ on the left-hand sidebar, then choose ‘Security’.
  • Further down, tap ‘Manage certificates’ to see a list of SSLs that Chrome has cached for you.
  • Browse the various tabs, choose an SSL, then press ‘Remove’ to wipe that SSL state.
  • When you’re ready, click on the ‘X’ or ‘Close’ button.
  • Restart Chrome.

If you still see the ERR_SSL_PROTOCOL_ERROR even after wiping the browser or SSL cache, it may be time to look at other programs. Deactivate antivirus software, browser extensions, and firewalls temporarily. Confirm that your system’s time and date are correct too.

How is the ERR_SSL_PROTOCOL_ERROR Shown in Other Web Browsers?

You could experience this error in every browser, and each may display its own message. Below, we’ll find out what you can expect to see in the most popular browsers.


Opera displays the ERR_SSL_PROTOCOL_ERROR with a message stating ‘This site can’t provide a secure connection’. It also makes you aware that an invalid response was delivered by the site. You can check out the troubleshooting tool if you tap the ‘Try running Windows Network Diagnostic’ option.


Chrome presents the ERR_SSLPROTOCOL_ERROR with the same message as Opera. It states that an invalid response has been sent by the site. You can either run the Windows Network Diagnostics or choose ‘Reload’ to try again.


Mozilla Firefox shows a fairly in-depth breakdown of the error. It will alert you to a failed attempt to make a secure connection and display the following error code: SSL_ERROR_RX_MALFORMED_HANDSHAKE.

Additionally, you’ll see a description of why the error occurred and how to handle it. You can get more information by clicking on the ‘Learn more’ option or retry the connection with the ‘Try Again’ button.


When using Microsoft Edge for browsing, the error is shown with a message warning you that ‘The connection for this site is not secure’. The code is presented below the error message. Edge gives you a clickable link to run Windows Network Diagnostics.


When a website is unable to give you a secure connection, it will deliver the ERR_SSL_PROTOCOL_ERROR instead. It could be caused by problems on the site’s side, including a missing SSL certificate or HTTPS not being forced.

You may see the ERR_SSL_PROTOCOL_ERROR when the issue is your browser, though its presentation can vary from one browser to another.

This error can be daunting when it first appears, but you have three simple techniques to fix it, whether you’re a website visitor or owner. Here’s a quick summary:

  • Verify that SSL is installed on your site, as enabling HTTPS without having a certificate can trigger an SSL connection error.
  • Force HTTPS on your website after installing SSL. You can do this via a hosting control panel, WordPress’s dashboard, or .htaccess file.
  • Wipe your browser’s cache, as this may be old and responsible for the connection error. Emptying the browser cache and SSL state enables existing information to be renewed by the browser.

Now that you’ve read our guide to fixing the ERR_SSL_PROTOCOL_ERROR, hopefully you’ll find troubleshooting this common issue much easier.

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