MacOS Sierra won't start – what to do?
- Start the Mac first or turn it on if it is turned off.
- Press and hold during the boot process, the keys [Cmd] + [Alt] + [P] + [R] to delete the permanent memory on the Macs.
- Release the keys when you hear the startup sound for the second Time.
- Your Mac should now work properly again.
- Basically, you should make sure that your Mac the new operating system supports.
- You can also try the Mac in safe mode to start, to fix the Problem.
Is your MacOS Sierra after the Update slowly, we will have in the next practice tip a few tips for you.