So setting up a new home server using latest Windows Server 2012 R2 Essentials.  Tried to connect to the domain using the Server Web Connect e.g. http://[ServerName]/Connect and I can see the webpage and download the connection exe e.g. ComputerConnect[ServerName].exe but I get the following error when running it:

Windows Server Essentials Connector Configuration Wizard

An Unexpected error has occurred. To resolve this issue, contact the person responsible for you network.

Fix:-

Seems like the Web Connect doesn't yet work for Windows 10. So you need to install the KB from Microsoft and install it on your Windows 10.

Windows Server Essentials Connector for Windows Server 2012 R2

Once installed in Windows 10 you have a new App.

Click Start, All Apps

Scroll down to "Windows Server Essentials" and run "Windows Server Essentials Connector Configuration Wizard".  Then run through the setup and all should be good.