I am trying to join the Exchange Server 2013 (Server 2012 Standard) on to Sever 2012 Essentials via the Set up Exchange Server Integration wizard.

The wizard keeps failing:

There was a problem configuring the Integration
An unknown error occurred.
Make sure that the computer is connected to the network, and then try again.
If you continue to experience this problem, restart the server and then try again.

Both Servers are connected to the same domain via AD. I can see both Servers on the network and gain access to each server.

I have noticed that the Exchange server does not show up in the Dashboard under Devices. I cant seem to find a way of connecting the Exchange Server to Server 2012 Essen

Run the /connect program to join the computer to the domain.  

Essentials can run connect on server 2012.   Manually join the domain if connect is misbehaving.  

Sorry not following? You've domain joined the second server. You've installed Exchange, yes? You sure that the member server is listed in ADUC as a member server?  

I have managed to connect the two servers together via AD, this does not give me the ability to fully manage user accounts from Server 2012 Essentials.