guard-livereload: "Could not connect to LiveReload server."

When I try to connect guard-livereload to the LiveReload Chrome extension I get this error in Chrome. I’m under Mac OS 10.9.3 with Ruby 2.0.0-p247 using rbenv.

Could not connect to LiveReload server. Please make sure that LiveReload 2.3 (or later) or another compatible server is running.

Here is the content of my Guardfile

guard 'jekyll-plus', :serve => true, :drafts => true do
  watch /.*/
  ignore /^_site/
end

guard 'livereload' do
  watch /.*/
end

And this is the output of guard in the terminal

WARN: Unresolved specs during Gem::Specification.reset:
      rb-inotify (>= 0.9)
      rb-kqueue (>= 0.2)
WARN: Clearing out unresolved specs.
Please report a bug if this causes problems.
15:17:18 - INFO - Guard here! It looks like your project has a Gemfile, yet you are running
> [#] `guard` outside of Bundler. If this is your intent, feel free to ignore this
> [#] message. Otherwise, consider using `bundle exec guard` to ensure your
> [#] dependencies are loaded correctly.
> [#] (You can run `guard` with --no-bundler-warning to get rid of this message.)
Configuration file: _config.yml
15:17:19 - INFO - Guard is using  to send notifications.
15:17:19 - INFO - Jekyll building...
    Server address: http://0.0.0.0:4000
  Server running... press ctrl-c to stop.
15:17:26 - INFO - Jekyll build complete ./ → _site
15:17:26 - INFO - Jekyll watching and serving at 0.0.0.0:4000/
15:17:26 - INFO - LiveReload is waiting for a browser to connect.
15:17:26 - INFO - Guard is now watching at '/Users/Damien/Documents/LBSRF'
[1] guard(main)> 15:17:28 - INFO - Browser connected.
15:17:28 - INFO - Browser disconnected.