Prohibited sign issue after OS update on macbook pro late 2011
I have a macbook pro late 2011 witb seirra. I got an update installation notification. Clicked on update, mac restarts and update installation in progress suddenly it gives me prohibited sign on the screen. Now i have tried restarting it but getting same error. I dont have a back up of my files. It would be great to get a solution wherein I can save my files as well.