Deal with more serious issues

When macOS won’t start, is unstable, or forgets hardware settings, try these tips

Start in safe mode

When your Mac won’t start up or behaves

oddly, there are many possible causes. Safe mode helps you narrow them down. It loads only essential kernel extensions, disables fonts you’ve installed in case any are corrupt, deletes various cached (temporary) files, and prevents startup and login items from opening.

See below for our quick guide to using safe mode to rule out your login items as the cause of startup problems. If you still have problems after that, a kernel extension (kext) could be the culprit. Don’t try to remove these manually; the safe way is to use an uninstaller provided with their associated app. To see which third-party kexts are installed – probably very few – open Terminal and type kextstat | grep -v com.

apple. Look over the output; most kexts give away their app’s identity. Any called ‘tun’ and ‘tap’ will be for a VPN (virtual private network). Use Google to look up any that are mysterious.