Firefox browser, version 74.0 from the beginning, completely give up on encryption protocol TLS 1.0 and TLS 1.1 support. By then, the browser will show through "Secure Connection Failed" error page to prevent users from accessing does not support TLS 1.2 or a later version of the site.
As early as 2018, Mozilla and other browser makers (including Google, Microsoft and Apple) announced plans to abandon TLS 1.0 and TLS 1.1 in 2020 to improve the security of Internet connection.
The latest encryption protocol TLS 1.3 Final version released in 2018, the major mainstream browsers have implemented support for the new agreement. But there are still some sites that did not migrate to the more secure a new agreement. Mozilla scan revealed mid-2019, the top 1 million sites have 8000 does not support TLS 1.2 or higher. Of course, and six months later, the situation may change.
▲ Source: Ghacks (the same below)
Starting Firefox 74, using TLS 1.1 or lower version of the site will fail to load in the browser. Not just Firefox, Chrome and other major browsers (such as Microsoft Edge, Apple Safari, etc.) should be in the same situation will occur.
In Firefox, the browser would throw an "Secure Connection Failed" error message with error code "SSL_ERROR_UNSUPPORTED_VERSION", and can not bypass the error (since removed support for TLS 1.0 and 1.1 from the browser). Therefore, it is recommended to maintain the sites have taken the initiative to actively update, so as not to interrupt the connection event occurs.
Finally, Firefox 74.0 Stable planned for 2020 March 10 release.