Firefox 81.0

This article explains why you may see a Secure Connection Failed or a Did Not Connect: Potential Security Issue error page and what you can do.

Firefox has been improved with the release of Firefox 81.0.1. This update has fixes for picture in picture, Blackboard course listings, along with several other fixes. Features are a big part of Firefox. From tabbed browsing, bookmarks, a built in session manager, private browsing, add-ons, sync, and more. Mozilla Firefox 81.0.2. Mozilla Firefox browser is a fast, full-featured Web browser. Firefox includes pop-up blocking, tab-browsing, integrated Google. Firefox for Desktop. Get the not-for-profit-backed browser on Windows, Mac or Linux. Firefox for Android. Firefox Release. October 13, 2020. Welcome to the Project on SourceForge. Most of our users download and install our apps through the Platform's built-in app store and then keep them updated using the platform's built in updater.

  • If you see a Warning: Potential Security Risk Ahead error page, see the What do the security warning codes mean? article.
  • To troubleshoot other error messages, see Websites don't load - troubleshoot and fix error messages.

Table of Contents

  • 1Secure connection cannot be established
  • 2Website issues

When a website that requires a secure (https) connection tries to secure communication with your computer, Firefox cross-checks this attempt to make sure that the website certificate and the connection method are actually secure. If Firefox cannot establish a secure connection, it will display a Secure Connection Failed or Did Not Connect: Potential Security Issue error page.

Secure Connection Failed

A Secure Connection Failed error page will include a description of the error, an option to report the error to Mozilla and a button. There is no option to add a security exception to bypass this type of error.

The error page will also include the following information:

  • The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
  • Please contact the website owners to inform them of this problem.

Did Not Connect: Potential Security Issue

Certain secure connection failures will result in a Did Not Connect: Potential Security Issue error page.

The error page will include a description of the potential security threat, an option to report the error to Mozilla and an button to view the error code and other technical details. There is no option to add a security exception to visit the website.

TLS version unsupported

Some websites try using outdated (no longer secure) Transport Layer Security (TLS) mechanisms in an attempt to secure your connection. Firefox protects you by preventing navigation to such sites if there is a problem in securely establishing a connection.Contact the owners of the website and ask them to update their TLS version to a version that is still current and still secure.

Starting in Firefox version 78, the minimum TLS version allowed by default is TLS 1.2. Websites that don't support TLS version 1.2 or higher will display a Secure Connection Failed error page with Error code: SSL_ERROR_UNSUPPORTED_VERSION and a message that This website might not support the TLS 1.2 protocol, which is the minimum version supported by Firefox.

The error page may also include a button, that will allow you to override the minimum TLS requirement.
Note: Mozilla plans to remove this option and permanently disable TLS 1.0 and 1.1 in a future version of Firefox. For more information, see this Mozilla page.

HSTS required

Other websites may require HTTP Strict Transport Security (HSTS) and will not allow access with an insecure connection.

Many security products use a feature that intercepts secure connections by default. This can produce connection errors or warnings on secure websites. If you see secure connection errors on multiple secure websites, updating your security product or modifying its settings may resolve the issue. See this article's section on Antivirus products for help with specific security products that can produce these errors, such as Avast, AVG and ESET software.

Alternatively, you can uninstall third-party security software and use Windows Defender, the built-in antivirus on Windows 8 and Windows 10.

Firefox uses certificates on secure websites to ensure that your information is being sent to the intended recipient and can't be read by eavesdroppers. An incorrect system date can cause Firefox to detect that the website's security certificate is expired or invalid. Make sure your computer is set to the correct date, time and time zone. For more information, see How to troubleshoot time related errors on secure websites.

These articles describe how to troubleshoot some specific secure connection errors:

  • Certificate Pinning Reports
  • Certificate contains the same serial number as another certificate

For a list and brief description of other secure connection errors, see NSS and SSL Error Codes at MDN Web Docs.

Other Languages:

Firefox 81.0.1 Slow

  • Stable:
  • Beta:

Mozilla Firefox 81.0

Mozilla Firefox is a fast, full-featured Web browser. Firefox includes pop-up blocking, tab-browsing, integrated Google search, simplified privacy controls, a streamlined browser window that shows a number of additional features that work with you to help you get the most out of your time online.

Installing Firefox was a fine , quick experience.A new feature checks your add-ons to see which ones you installed and which ones come from third-party vendors, such as security suite makers. The browser will now ask you if you'd like to disable any of these third-party add-ons.

Mozilla Firefox 81

The menu bar has been squished into an orange button on the upper left, with menu options spread across two columns.the menu makes it much easier to get to bookmarks, add-ons, and history, as they now all live on one Menu pane.

Firefox is built on top of the powerful new Gecko platform, resulting in a safer, easier to use and more personal product.Mozilla plans to crowdsource its performance data to learn more about how the browser performs in real-world situations.

Firefox's features are robust and generally competitive. The most important feature in the modern Firefox is Sync.Sync now smoothly syncs your bookmarks, passwords, preferences, history, and tabs, not only with other computers, but also with your Android version of Firefox.