We are migrating away from a 2011 SBS server to a Virtualized Windows 2012 R2 standard with Exchange 2013. We have both exchange and AD up and running on separate Virtual Machines, with the CA role installed on the DC. When we came to configure the Essentials Role on the DC, it failed since the CA is already running on it. Is it possible to temporarily, uninstall the CA, deploy the essentials role and configure it, then re-enable the Certificate Authority on the same server? Or are the CA and essentials Roles mutually exclusive and cannot be run on the same server at all? The client needs to retain the Remote Web Workplace type functionality that was a part of the Old SBS 2011 server configuration.