parse_access_token': undefined method `split' for nil:NilClass (NoMethodError)

[millisami]

Installed the gem.

Following is my ~/.geppetto/settings.yaml file

dev:  &defaults
  app_id: "276194505816510"
  secret: "069f3d6d766334bffbcaa1fc31c1997c"
  # http://developers.facebook.com/docs/authentication/permissions/
  default_permissions: [read_stream, offline_access, publish_stream, friends_hometown, friends_location]
  app_url: http://localhost:3000/
qa:
  app_id: <-- YOUR APP ID -->
  secret: <-- YOUR APP SECRET -->
  <<: *defaults

Now when run the list cmd:

geppetto list
/Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/koala-1.0.0/lib/koala.rb:255:in `parse_access_token': undefined method `split' for nil:NilClass (NoMethodError)
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/koala-1.0.0/lib/koala.rb:251:in `get_token_from_server'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/koala-1.0.0/lib/koala.rb:181:in `get_app_access_token_info'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/koala-1.0.0/lib/koala.rb:185:in `get_app_access_token'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/koala-1.0.0/lib/koala/test_users.rb:18:in `initialize'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/geppetto-0.9.8/lib/geppetto/cli.rb:19:in `new'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/geppetto-0.9.8/lib/geppetto/cli.rb:19:in `initialize'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/thor-0.16.0/lib/thor.rb:271:in `new'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/thor-0.16.0/lib/thor.rb:271:in `dispatch'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/thor-0.16.0/lib/thor/base.rb:425:in `start'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/gems/geppetto-0.9.8/bin/geppetto:35:in `<top (required)>'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/bin/geppetto:23:in `load'
  from /Users/millisami/.rbenv/versions/1.9.3-p194/gemsets/global/bin/geppetto:23:in `<main>'

What is causing this error?