Event 2103 - Active Directory contact issues
Symptoms
- Active directory users and computers possible error
Naming Information cannot be located because:
The Server is not operational.
Contact your system administrator to verify that your domain is properly configured and is currently online. - Event 2103 - Directory Service
The Active Directory Domain Services database has been restored using an unsupported restoration procedure. - The NetLogon service will be "Paused" on the DC. Every reboot will lead to it being "Paused" again.
Resuming the service will allow the domain to work temporarily
Fixes
Check HKLM\System\CurrentControlSet\Services\NTDS\Parameters\DSA Not Writable (REG_DWORD), it's probably 0x4.
Delete "DSA Not Writable" (REG_DWORD) from registry and reboot the server.
Event 1394
After resolving the issue you will see event 1394
All problems preventing updates to the Active Directory Domain Services database have been cleared. New updates to the Active Directory Domain Services database are succeeding. The Net Logon service has restarted.
Follow up
Ensure that Verification of outbound replication failed does not become an issue by checking for the specified associated event logs. You may only need to enable replication via the fixes listed.