I updated my MacBook Air to OS X El Capitan (OS X 10.11) last week, and subsequently hit two issues.
The first issue was that Outlook would not work. This luckily has been fixed with an adapt from Microsoft.
The second issue is unlikely to be resolved. The Ecamm BT-1 Bluetooth Wireless Webcams that I use with ScreenFlow to record class presentations no longer work after the El Capitan upgrade. Ecamm discontinued the camera several years ago, so I don’t see any options beyond reverting to an earlier version of the OS. There don’t seem to be any viable alternatives yet. The Logitech Broadcaster Wi-Fi Webcam does not have an El Capitan driver, the HuddleCam Air HD is too expensive.
Sigh.