Yesterday (few days after some update), my macbook working on el capitan osx, started to going crazy. It was stuck few times on loading screen (but somehow after few attemps with many different solutions, I turned on finally. But then, I cannot open any application. That problem (for that moment) was also solved by repairing permissions.
But then, few hours later, after turning computer off, I cannot turn it off again. It's stuck on loading screen, none of solution found here and there are not working - can't reinstall, can't do anything. Safe mode is loading, but can't solve anything.
And now, when I tried to upload osx from usb, my mac put that on screen:
OS X could not be installed on your computer. Unable to unmount voulume for reparir. Quit the installer to restert your computer and try again
Any ideas what's wrong? Any solutions? Please, help!