According to the notice:

We are removing support for insecure ciphersuites using the CBC mode, specifically ECDHE-ECDSA-AES128-SHA, which your browser software relies on to connect to our sites. This is usually caused by outdated browsers, or older Android smartphones. Apple users should upgrade to iOS 9 or MacOS X 10.11 or higher. Or it could be interference from corporate or personal "Web Security" software, which actually downgrades connection security.

You must upgrade your web browser or otherwise fix this issue to access our sites. This message will remain until November 1, 2020. After that date, your browser will not be able to establish a connection to our servers.