Services & Such Listed as Users/Groups

Today I discovered that there's a whole list of services listed as Users and groups. Does anyone know what the deal is with this? I am using the correct version of Mac Server 4.1.

I tried deleting them, but then my mini froze when accessing the finder Users control panel. It would also ask for my admin password (accessing the server app), and even though it was correct denied access saying it was incorrect.

I deleted server app and reinstalled it from Mac App Store. I marked the old server folder in Library as "Server.old". Even after reinstalling, the same Users/Groups are listed.

Any help would be very much appreciated.