Error shown while trying to set up shapado in laptop (Mac OS)

Hello,

I am new in Shapado. I want to set up shapado in laptop (MAC OS), but when I want to access to http://localhost.lan:3000, the following error message occurs:

"NoMethodError in Questions#index

Showing /Users/sciruela/Documents/shapado/shapado/app/views/shared/_login_drop_down.html.haml where line #10 raised:

Undefined method `[]' for nil:NilClass
Extracted source (around line #10):

7:   = link_to provider.titleize, '/users/auth/facebook', :class => 'auth-provider Facebook', :id => 'facebook'
8:   – else
9:   %li
10:  = link_to provider.titleize, multiauth_url(provider), :class => "auth-provider #{provider}", :id => provider
11:
12:  -if current_group.allow_any_openid
13:  %li

Trace of template inclusion: app/views/shared/_login_menu.html.haml, app/views/shared/_topbar.html.haml, app/views/layouts/application.html.haml

Rails.root: /Users/sciruela/Documents/shapado/shapado

Application Trace | Framework Trace | Full Trace
app/views/shared/_login_drop_down.html.haml:10:in `block in

_app_views_shared__login_drop_down_html_haml__1123238317393261506_2159776840'
app/views/shared/_login_drop_down.html.haml:2:in `each'

app/views/shared/_login_drop_down.html.haml:2:in `_app_views_shared__login_drop_down_html_haml__1123238317393261506_2159776840'

app/views/shared/_login_menu.html.haml:6:in `_app_views_shared__login_menu_html_haml___434956048083202339_2193663100'

app/helpers/application_helper.rb:36:in `multiauth_dropdown'
app/views/shared/_topbar.html.haml:21:in `_app_views_shared__topbar_html_haml___2782218627514502243_2204427320'

app/views/layouts/application.html.haml:10:in `block in _app_views_layouts_application_html_haml___4514694021451724572_2205033860'

app/helpers/layout_helper.rb:74:in `call'
app/helpers/layout_helper.rb:74:in `block in ie_tag'

app/helpers/layout_helper.rb:72:in `ie_tag'
app/helpers/layout_helper.rb:79:in `ie_html'

app/views/layouts/application.html.haml:2:in `_app_views_layouts_application_html_haml___4514694021451724572_2205033860'

app/controllers/application_controller.rb:122:in `block (2 levels) in find_questions'
app/controllers/application_controller.rb:121:in `find_questions'

app/controllers/questions_controller.rb:67:in `index'
lib/sso_strategy.rb:18:in `call!'
app/middlewares/dynamic_domain.rb:17:in `call'

Request

I need to solve this error message. 

Please help me. 

Thanks a lot.