The OS X El Capitan v10.11.3 Update improves the stability, compatibility, and security of your Mac, and is recommended for all users.
- Fixes an issue that may prevent some Mac computers from waking from sleep when connected to certain 4K displays.
- Third-party .pkg file receipts stored in /var/db/receipts are now retained when upgrading from OS X Yosemite.
For detailed information about the security content of this update, see Apple Security Updates.
How to update your Mac
Some updates become available only after installing other updates. You should install all available updates, and allow installation to complete without interruption. You can also get this update from the Apple Support Downloads site. You might have unexpected results if third-party OS X modifications have been installed, or you modified OS X in other ways.