Adobe has discovered the compatibility issues listed below with running Lightroom CC 2015 or Lightroom 6 with Mac OS 10.11 (El Capitan).
We recommend that customers do their own testing on a nonproduction partition to ensure that new operating systems work with their current hardware and drivers.
If you do encounter issues not already documented, feel free to report them on our feedback site.
Tethering Nikon cameras is supported in El Capitan as of Lightroom CC 2015.4 and Lightroom 6.4.
Direct tethering of most Leica cameras using Lightroom CC 2015 and Lightroom 6 is not currently supported on El Capitan.
Tethering Leica S (Typ 007) cameras is supported on El Capitan through the "Leica Tethered Plug-in" which can be downloaded from the Leica Owners' Area.
Adobe recommends that customers who rely on Lightroom for tethering Leica cameras, other than the Leica S (Typ 007), do not upgrade to El Capitan at this time.
Update Mac OS X (El Capitan) to version 10.11.4 correct this issue.
If Lightroom is put in native Mac OS X full screen mode, there are some inconsistent behaviors:
To exit native full screen mode, move the cursor near the top of the screen so the application bar with minimize/maxize buttons are visible. Click the green button (the button on the right of the three buttons) to exit native full screen mode
If you cmd + tab away from Lightroom to another app and come back to Lightroom using cmd + tab while a dialog is open in native full screen mode, the main Lightroom app window is active instead of the dialog. To access the dialog window, use the 3-finger gesture to swipe up and select the space/window with the dialog you want to access to commit or cancel it.