Be carefull with update from version 10.11.5 to 10.11.6. I updated from version 10.11.5 to 10.11.6 and i have a lot of problems. Safari does not work. Parallels does not work. system prferences does not work. Google chrome .... The update finish without problems but when the system reboot .... the system have a lot of different problems. I had to recovery my system from time machine. This update fail or has some problems or .... is do not enought tested.