Exchange 2013 SP1 readiness check failing

Trying to install our first Exchange 2013 SP1 server on Windows 2012 R2 in our datacentre, the readiness check fails with:

• Error:
  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
  

There are many more errors relating to Enterprise admin rights etc.

Please note that:

• My account is Domain admin, Schema admin and Enterprise admin member, it always has been.
• I tried the built-in AD Administrator which of course is part of the groups as well, no difference.
• Active Directory is at 2008 R2 for domain and forest functional levels.
• I tried rejoining the new Exchange designated server to the domain
• I've installed RSAT-ADDS, the Managed API 4.0 and all the other windows roles via powershell

• There is a local domain controller that is a global catalog server on the new Exchange server subnet
• I tried running the Exchange Setup on a different server on the same subnet as where the active 2010 Exchange server resides as well as the FSMO AD role holder resides, this works fine. I even did the AD prep from there no problem, that made no difference on the datacentre server
• AD replicates fine between the FSMO role holder and the Datacentre (no errors in dcdiag or repadmin /showrepl)

This error is in the event log:

The description for Event ID 4027 from source MSExchange ADAccess cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.

If the event originated on another computer, the display information had to be saved with the event.

The following information was included with the event: 

ExSetupUI.exe
6724
Get Servers for domain.local
TopologyClientTcpEndpoint (localhost)
3
System.ServiceModel.EndpointNotFoundException: Could not connect to net.tcp://localhost:890/Microsoft.Exchange.Directory.TopologyService. The connection attempt lasted for a time span of 00:00:02.0475315. TCP error code 10061: No connection could be made because the target machine actively refused it 127.0.0.1:890.  ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it 127.0.0.1:890
   at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.Sockets.Socket.Connect(EndPoint remoteEP)
   at System.ServiceModel.Channels.SocketConnectionInitiator.Connect(Uri uri, TimeSpan timeout)
   --- End of inner exception stack trace ---

Server stack trace: 
   at System.ServiceModel.Channels.SocketConnectionInitiator.Connect(Uri uri, TimeSpan timeout)
   at System.ServiceModel.Channels.BufferedConnectionInitiator.Connect(Uri uri, TimeSpan timeout)
   at System.ServiceModel.Channels.ConnectionPoolHelper.EstablishConnection(TimeSpan timeout)
   at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at System.ServiceModel.ICommunicationObject.Open()
   at Microsoft.Exchange.Net.ServiceProxyPool`1.GetClient(Boolean useCache)
   at Microsoft.Exchange.Net.ServiceProxyPool`1.TryCallServiceWithRetry(Action`1 action, String debugMessage, WCFConnectionStateTuple proxyToUse, Int32 numberOfRetries, Boolean doNotReturnProxyOnSuccess, Exception& exception)

the message resource is present but the message is not found in the string/message table