Thru a series of misfortunate circumstances I have acquired a client that had either botched (or had another do the botching) of a Essentials\Exchange (in a VM environment) config, Essentials is running okay and Exchange is running okay except the part where
on premises integration is performed.
I've gone through the standard setup checklist (Integrate an on-premise Exchange Server with Windows Server Essentials 2012http://technet.microsoft.com/library/jj200172 ) and even tested enabling and disabling and re-enabling on my home lab setup without error;
What I know so far
there seems to have been multiple attempts at adding an Exchange Server or they decided on version upgrades (I found leftover server names in ADSI)
there is no logging of the why or reason on the Wizard failures (there is very very little documentation on the back end of this feature) the Error message is sadly lacking in any descriptive message
I have dug down to the OPEIntegration configs but there is little guidance there as well, searching the registry has yielded no results
I think, but am not sure of, an Original 2 server deployment of essentials and Exchange (probably 2010) was initially deployed when 2013 was released they tried a deployment on a new VM thinking that other then the uninstall little else had to be done.
Exchange seems to be working (had to delete/recreate some users for inconsistent mailbox errors) creating mailboxes in Exchange and not through the Essentials interface, users are sending and receiving mail
More docs on the backend processes for essentials would be nice I love SBS but lets face it some of the ALL in One stuff is badly documented getting the linked "find out more about this error" pages updated would be nice.....