Mac OS X 10.11.3 was an update to Mac OS X 10.11 released on January 19, 2016.
This update includes the following:
- 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.