On new 2016 server installing exchange I get the same error, so I proceeded to just PrepareSchema on the Essentials server so there is no DNS issue and get the same error ?? ( running on Essentials server should not be an issue as it is not installing Exchange Server just preparing AD but cannot comment but getting same error on proposed exchange server )
The Active Directory schema isn't up-to-date, and this user account isn't a member of the 'Schema Admins' and/or
'Enterprise Admins' groups.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.SchemaUpdateRequired.aspx
Setup encountered a problem while validating the state of Active Directory: Couldn't find the Enterprise Organization
container. See the Exchange setup log for more information on this error.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.AdInitErrorRule.aspx
The forest functional level of the current Active Directory forest is not Windows Server 2003 native or later. To
install Exchange Server 2016, the forest functional level must be at least Windows Server 2003 native.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.ForestLevelNotWin2003Native.aspx
Either Active Directory doesn't exist, or it can't be contacted.
For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.CannotAccessAD.aspx
The Exchange Server setup operation didn't complete. More details can be found in ExchangeSetup.log located in the
<SystemDrive>:\ExchangeSetupLogs folder.
1. The user is a member of Schema Admin and Enterprise admin.. its the Administrator ! Yes administrator could be not a member but in SBS land it is and I even set priority group to Schema Admin when all other installs Administrator priority group was only user.
2. Forest is not 2003 or later.. Oh yes it is... see attached.. scrubbing out clients name 2 letters domain name. Only difference with this site, could this be an issue ?
3. AD doesn't exist, Im doing it on the DC ?
The errors seem generic, seems if one error it produces all this but wondering if anyone had the issue and pointers? The forest level issue proves it, error says its not 2003 or later when it is.