Not able to login using network account after upgrade to High Sierra
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.


Login with local administrator account
Go to System Preferences > Users &amp; 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
Close Directory Utility and reboot the computer
Repeat steps 1 and 2
Press Join near Network Account Server
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.


Optional Step - Go to System Preferences > Users &amp; Groups
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
Optional Step - Press Show more > Check "Create mobile login at login" > Uncheck "Require confirmation before creating a mobile account" 
Log out (may need another reboot)
Login with network account by selecting the user from the list or using your name on password (depends on "Display login windows as" setting)