Since August 03, 2018, Cisco only allows connections using Transport Layer Security (TLS 1.2). Users connecting from operating systems and browsers that do not support or are not configured to use TLS 1.2 will not be able to start or join meetings.

If TLS 1.2 is disabled in your browser, the connection between Webex web servers and your browser will not be established. Any code changes in the Webex client will not take effect on your computer. Users will receive the following error, while accessing the Webex site:

Cisco Webex Business Suite 33.6 and above
If the site is enabled with Modern View, users connecting from operating systems and browsers that do not support, or are not configured to use, TLS 1.2, will receive the following error:
For help enabling TLS 1.2 and more info about the changes, see: TLS 1.2 Required in Cisco Webex Meetings