(setq server-socket-dir "~/.emacs.d/server")
  (server-start)

emacsclient: can't find socket; have you started the server?
To start the server in Emacs, type "M-x server-start".
emacsclient: No socket or alternate editor.  Please use:

    --socket-name
    --server-file      (or environment variable EMACS_SERVER_FILE)
    --alternate-editor (or environment variable ALTERNATE_EDITOR)