Following this first part of this tutorial:
http://guides.spreecommerce.com/developer/extensions_tutorial.html
I get the following error after running bundle exec rails g spree_fancy:install and restarting my server.
NoMethodError - undefined method empty?' for nil:NilClass: spree_frontend (2.1.3) app/views/spree/shared/_products.html.erb:4:in_455e18500ee799576c5d38975ccbca34'