Sometimes i have problems with my Xcode server running on a separate mac mini. On my Macbook the Xcode bots won't show up and/or I can't connect to the Xcode server in the settings pane.
My Xcode server running on a mac mini also shows me "Error Reading Settings" error sometimes...
I also reset Xcode server already but after a while it doesn't work again.
UPDATE
Currently it's working again since a couple days. What my changes were:
I was having only the "xcodeserver" user on the server machine. I added my personal account and I changed it to have the xcodeserver user running the service and the tests and my personal user to run the Server App. I'm really not sure what it changed under the hood, but it works for now.