You will still need local and Active Directory administrator account or a local Apple Administrator account if using Open Directory. Go to System Preferences > Users & Groups 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…
Network Accounts Are Unavailable – High Sierra, AD, and Open Directory
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