Auto Shutdown Mac – Schedule Power Off After High Sierra Upgrade

You will still need local and Active Directory administrator account for this to work, but here's the exact steps I took to fix this issue.

1. Login with local administrator account
2. Go to System Preferences > Users & Groups
3. Press Login Options > Unlock > Press Edit near Network Account Server > Open Directory Utility > Unlock > Select Active Directory and press "Edit settings for the selected service" button at the bottom > Unbind > Enter Active Directory administrator credentials and finish the unbinding process
4. Close Directory Utility and reboot the computer
5. Repeat steps 1 and 2
6. Press Join near Network Account Server
7. Enter your domain (ad.example.com) and Active Directory administrator credentials.

Assuming your AD account is not entirely network account (created on your local system and you can use it without network access) you should also set settings in 8-10 steps.

8. Optional Step - Go to System Preferences > Users & Groups
9. Optional Step - Login Options > Unlock > Press Edit on Network Account Server > Open Directory Utility > Unlock > Select Active Directory and press "Edit settings for the selected service" button at the bottom
10. Optional Step - Press Show more > Check "Create mobile login at login" > Uncheck "Require confirmation before creating a mobile account"
11. Log out (may need another reboot)
12. Login with network account by selecting the user from the list or using your name on password (depends on "Display login windows as" setting)

I had the same problem with an iMac,

just delete the update program from your mac and re download it from the App Store.

If that won't work you should make a Backup with Timemachine and reset your Mac. Try to update again. if it works, recover your data from the backup.

Check this link if you need help with the reset of your system. https://support.apple.com/kb/PH25649?locale=de_DE&viewlocale=de_DE