Mac Connector Setup - Registration failed - Cannot establish connection with the registration service.

When I run the Connector for Mac I get the error Registration failed: Cannot establish connection with the registration service.

The last entry in my "Windows Server.log" is "Apr  9 16:13:43 CHARLESs-iMac.local WSL[717] <Error>: /Users/xcbusr/macbuild/Request/F2E65C6F-F0F2-45FA-AFD9-10DBF661EF50/MacUtils/RegistrationManager.m:364 Request failed"

If I go to the Windows Server 2012 Essentials Dashboard, the Mac is listed under Devices. However, it is listed as Offline with no details and the connector is not installed on the client.

I am running OS X 10.8.3 and trying to connect to Windows Server 2012 Essentials.