ERR_SSL_VERSION_OR_CIPHER_MISMATCH error and how to fix it?

The ERR_SSL_VERSION_OR_CIPHER_MISMATCH error notice will be shown automatically by the browser when the user's browser and the web server are unable to support the same SSL protocol version.

Updated: 31 May, 23 by Susith Nonis 10 Min

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Every time you attempt to connect to a website, a website's SSL certificate is automatically verified by web browsers. It serves as evidence that the website you are accessing is legitimate and that the proper security procedure has been used to protect your connection.

A TLS handshake is what is happening here. Users' computers and web servers can communicate securely using the TLS (Transport Layer Security) protocol. Let's say that, during the TLS handshake, the user's browser and the web server are unable to support the same SSL protocol version or cypher suite.

In that situation, the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error notice will be shown automatically by the browser.

The browser uses the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error message to prevent you from visiting dangerous websites. Additionally, a website can use an unsupported protocol containing security holes, which could be dangerous for your device or the data you send to the website.

There are several reasons why a web server and browser won't support the widely used SSL protocol, leading to this error:

  • SSL certificates that are invalid are among the causes of the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error. The SSL certificate for the domain may have been issued for a different domain name alias, resulting in a certificate mismatch error.
  • Old TLS versions can also cause this error. The web server may employ an outdated TLS version no longer supported by modern web browsers.
  • OS and outdated web browsers may not be able to use the most recent TLS version.
  • A Google project called the QUIC protocol is an alternative to popular security measures but may result in this error.
  • The cached information in a web browser might not reflect a website's security upgrade.
  • This error can also come from an antivirus program setup error that causes a false warning.

It's vital to note that this error only appears on websites that secure access and data transfer with HTTPS encryption and SSL certificates. The URL bar of websites that employ these encryptions displays a lock icon.

Despite the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error’s complex and daunting appearance to novices, it is simple to resolve.

Verify the SSL/TLS certification

First, you have to check the validity and expiration date of your website's SSL/TLS certificate. Your SSL/TLS certificate may be to blame for the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error if it is out of date or invalid.

You can use various online tools to examine the SSL certificate for your website, such as Qualys SSL Labs, which will grade the SSL connection and point out any inconsistencies with the web server.

The program will also let you know whether the SSL/TLS certificate needs to be updated if it is outdated. It's easy to utilize the Qualys SSL Labs tool. As the tool prepares the findings of its server test, enter your website's URL, take a seat, and relax.

The SSL/TLS certificate will be evaluated by the program during the test to ensure that it is reliable and valid. After that, it will look at three crucial aspects of the server's configuration: protocol support, Cipher support, and Key exchange support.

When the tool is finished, it will compute the test results and give you a grade (such as an "A" or "B"). Using Qualys SSL Labs, you can find further issues that are known to cause the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error.

Check if there is a certificate name mismatch.

Your SSL certificate serves as evidence that your website is wholly legitimate. The name on the certificate and the name of your domain must coincide. A reputable CA (Certificate Authority) must also provide the SSL certificate.

According to SSL Labs, a mismatch can be any of the following:

  • Despite sharing an IP address with another website that does, the intended site does not employ SSL.
  • Although the website is no longer active, the domain still directs users to the previous IP address, which is now used by another website.
  • A content delivery network (CDN) used by the website does not support SSL.
  • The website for which the domain name alias is used has a different name, but the alias was left out of the certificate.

Verify if an outdated or unsupported version of TLS is being deployed

TLS version 1.2 or above should ideally be used by all hosting providers. Because some users may be using outdated web browsers and operating systems that continue to support an earlier version of the TLS protocol, you should also assure backward compatibility.

TLS version 1.3 was released in August 2018 and offered improved security and faster transfer rates. If your hosting company does not support TLS 1.2 at the very least, it might be time to find another one to fix the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error.

Delete cache and cookies from your browser

Quite a few local SSL certificate issues can be resolved by clearing the cache and cookies in your web browser. Depending on the browser and operating system you are using, the procedures to do this can be different.

To do this, most browsers feature the hotkey combination CTRL+SHIFT+DELETE. Be careful when doing this since if you don't uncheck these settings when deleting your browser data, you can lose your saved logins and browsing history.

If you use Chrome, follow these instructions to clear the cache:

  • In the browser's top-right corner, tap the ellipsis, then select "Settings."
  • Locate the "Privacy and security" section by scrolling down the list of choices.
  • Select "Clear browsing data" from the menu.
  • A new window will appear; select the "Cached photos and files" option.
  • Select the deletion timeframe from the drop-down menu before tapping the "Clear data" button.
  • Chrome must be restarted to finish the operation.

Go to your website to see if the error has been resolved after clearing the cache. If the issue persists, you might have to utilize your browser's 'clear SSL state' option from the OS's settings to fix the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error.

Deactivate your Firewall or Antivirus software

If you have misconfigured your firewall or antivirus software, it can be one of the causes of ERR_SSL_VERSION_OR_CIPHER_MISMATCH error. The reason is that improper configuration or the software's certifications may cause erroneous warnings and label a safe site as hazardous.

It is suggested that you temporarily disable the antivirus program to determine whether it is the cause of the error to prevent worse problems. However, removing the automatic SSL scanning capability in antivirus software should eliminate the problem notice without shutting down the antivirus system altogether.

Enable TLS 1.3 support

Between your browser and the server, TLS offers security. This layer directly replaces the SSL technology. TLS 1.3 is already supported by most online browsers, including Google Chrome. To enable TLS support in your browser if you're using an older version of Chrome, take the following actions:

  • Activate Google Chrome.
  • In Chrome’s address bar, type ://flags and then hit enter. 
  • Type TLS into the search box to find it.
  • TLS 1.3 support should be set to Enable.

The website you wish to access may occasionally use TLS 1.0 or TLS 1.1. Newer browsers will decline the connection and may display the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error.

A feature in newer versions of Google Chrome makes it mandatory to deprecate earlier TLS versions. However, by doing the following, you can disable that to connect to a website using an earlier TLS version:

  • Activate Google Chrome.
  • In Chrome’s address bar, type ://flags and then hit enter. 
  • Look for TLS.
  • Deprecation of old TLS versions must be enforced.
  • Select Disable from the drop-down menu by clicking on it.

Use Cloudflare to set up SSL

A misconfiguration of the Cloudflare and SSL settings may be one of the causes of ERR_SSL_VERSION_OR_CIPHER_MISMATCH error. The SSL Labs program will demonstrate that the certificate is incorrect when this is the cause of the error message.

The mentioned strategies should help you fix the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error in no time, although occasionally, they may not.

For instance, the issue may also be caused by outdated operating systems or browsers. To see if this is the problem, a simple test is to visit the website using a different, up-to-date device. If it works, it means the issue is with your operating system or browser.

Earlier browser versions may not support TLS 1.3 and other contemporary software versions. Still, it's also possible that an outdated OS version is to blame since modern browsers no longer support them.

Reinstalling the browser might still fix the issue. Install the most recent browser version from the official website after uninstalling the older version from your device. However, if you use an outdated OS like Windows Vista or XP, reinstalling the browser won't resolve the problem.

These operating systems certainly wouldn't work with the most recent browser version. If so, you must update the operating system to the well-liked Windows 10. 

A browser verifies the SSL certificate whenever a person tries to access a website. They do this to ensure the website is authentic and has put the proper protocols in place to guarantee the security of the user's connection.

This procedure, also known as TLS, ensures safe communication between a user's device and a web server.

What happens if, throughout this process, a web server or browser cannot implement a standard SSL protocol version or cypher suite? In this situation, The ERR_SSL_VERSION_OR_CIPHER_MISMATCH error notification would be automatically shown by the browser.

The causes of ERR_SSL_VERSION_OR_CIPHER_MISMATCH error are different; however, there are easy strategies you can employ to fix ERR_SSL_VERSION_OR_CIPHER_MISMATCH error easily. 

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Susith Nonis

Susith Nonis

I'm fascinated by the IT world and how the 1's and 0's work. While I venture into the world of Technology, I try to share what I know in the simplest way with you. Not a fan of coffee, a travel addict, and a self-accredited 'master chef'.