The ERR_SSL_VERSION_OR_CIPHER_MISMATCH error is displayed in your browser when the browser is unable to establish a secure connection to the web server. SSL certificates are common theses as they provide a secure and encrypted connection between a website and a web browser. SSL certificates are used in situations where you need to encrypt sensitive data such as credit card numbers and personal information so that you can securely accept payments, transfer data, log into web forms, etc. But today, SSL certificates are becoming the standard protocol. for any website, and Google is pushing all webmasters to implement SSL certificates on their websites. Today we are going to show you how to fix the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error.

All popular browsers such as Chrome, Firefox, IE or Safari support SSL certificates. When a problem occurs with an SSL certificate, the web browser brings up an error message to help you understand the problem better. One of the error messages you see in your web browser ERR_SSL_VERSION_OR_CIPHER_MISMATCH… This will block access to the website, so it is very important to find out what is causing this error.

Here is a screenshot of what the browser will display.

“A secure connection could not be established because this site is using an unsupported protocol. Error code: ERR_SSL_VERSION_OR_CIPHER_MISMATCH “.

Reasons causing the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error

This problem usually occurs when you are using an old web browser or operating system, but sometimes there can be other reasons, such as a problem with the SSL certificate. There are some simple steps to help you determine the cause of the problem.

  • SSL certificate error
  • Browser caching and cookies are not cleared
  • TLS 1.3 support not included
  • QUIC protocol not disabled
  • Website blocked by Anti-Virus or Firewall
  • Other reasons

The following are possible solutions for error ERR_SSL_VERSION_OR_CIPHER_MISMATCH.

1. Check the SSL certificate

Of course, one of the first steps in debugging this issue is to check the SSL certificate and make sure everything is in order. To check if everything is ok with your SSL certificate, you can use a free online SSL verification tool. There are many free online services that allow you to do an in-depth analysis of the SSL certificate set for that particular website. We can recommend that you use the one provided by Qualys SSL Labs as it is very complete.

If you are using our Linux VPS hosting and you are having problems with the SSL certificate installed on your server, you can contact our Linux specialists and they will help you solve the problem immediately. They are available 24/7.

2. Clear your web browser history / cache.

Another solution for ERR_SSL_VERSION_OR_CIPHER_MISMATCH error is to clear saved web browser data like history / cache. This step may differ depending on which web browser you are using. If you are not sure how to clear the saved data for your browser, you can search Google for information on what actions you need to take to achieve this goal. Some web browsers allow keyboard shortcuts, so if you hit CTRL + SHIFT + DELETE, you will immediately have access to a blank browsing data page.

Once you clear the saved data in your web browser, you can try to access the website and see if that fixed the problem.

3. Enable TLS 1.3 support in your web browser.

Another common solution for the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error is to enable TLS 1.3 support in your web browser. Google Chrome allows you to install a minimum SSL / TLS version. Enter string in search chrome://flags and press Enter… Then look for TLS 1.3… This setting can be enabled in your web browser. If this setting is disabled, you can enable it and close the tab. You need to restart your web browser for the changes to take effect.

4. Disable QUIC protocol

If the QUIC protocol is enabled in your browser, you can also try disabling it. Open Google Chrome, enter string in search chrome://flags and press, Enterto open the settings page. Search, Experimental QUIC protocoland if this option is enabled, disable it. After making your changes, close the tab and restart your web browser for the changes to take effect. Then try accessing the website again and check if the problem is fixed.

5. Disable your anti-virus software.

Antivirus software installed on your local computer can also block access to the website. You can temporarily disable your antivirus software and try to access the website again. If that doesn’t fix the problem, you can also check your firewall and make sure the website isn’t added to the firewall blacklist.

6. Other solutions

If none of the suggested solutions solved the problem, you can try reinstalling your web browser and / or extensions that are enabled in your web browser. Also, if you are using an older operating system like Windows XP, you might want to consider upgrading your operating system. Newer technologies such as TLS 1.3 and the latest encryption suites are not supported on older systems.