MacOS Sierra won't start: you can do that

If MacOS Sierra suddenly does not start, you can usually fix it with a shortcut. Find out in our practical tip how problem solving works.

MacOS Sierra won't start - what to do?

1. Restart your Mac first, or turn it on if it's turned off.
2. Press and hold [Cmd] + [Alt] + [P] + [R] during startup to clear the Mac's permanent memory.
3. Release the buttons when you hear the start sound a second time.
4. Your Mac should now work properly again.
5. Basically, you should make sure that your Mac supports the new operating system.
6. You can also try starting Mac in Safe Mode to fix the problem.