Cant install OS X Sierra: requires OS X Server update? I have a late 2012 Mac Mini, whose compatibility with Sierra I have verified. The Mac Mini is currently on OS X El Capitan. I am trying to update it to Sierra and when I get to the step of selecting the destination disk, I get a popup that says: 

"macOS Sierra supports macOS Server version 5.2. To upgrade your server data you will first need to install OS X 10.10 or 10.11 and OS X Server version 4 or 5."

There is no Server app installed in the machine. Maybe it was installed before my time under another account and then uninstalled.

What can I do to upgrade to Sierra without having to install the Server app? I have to upgrade to install the latest Xcode etc.
The answer can be found on the Apple message boards and I can confirm this worked for me:


As root using sudo command from Terminal, delete the /Library/Server folder using the following command: sudo rm -rf /Library/Server
Within Finder, delete "Server" application from the "Applications" folder.


I realize you did remove the server.app folder, but the Library/Server folder must also be removed and was hidden from the finder. I only found it through terminal.

The person on the apple forum must have been from the team and knew what the installer was looking for.