Flash Player 11.2 does not detect the Adobe Connect 8 Linux Add-in. Even if the Add-in is installed, you cannot launch meetings on Linux in the Add-in. Therefore, no Add-in specific functionality, like screen-sharing, is available. Meetings open in the browser.
Upgrade Linux Flash Player to the latest 18.104.22.1681 (or later) version from get.adobe.com/flashplayer/.