```ruby
require 'rabl'

require 'spree/core'
require 'spree/auth'

require 'spree/api/controller_setup'

module Spree
  module Api
  end
end

require 'spree/api/engine'
```

Move rabl require to *after* spree/core has loaded Rails
user
```ruby
require 'spree/core'
require 'spree/auth'

require 'spree/api/controller_setup'

require 'rabl'

module Spree
  module Api
  end
end

require 'spree/api/engine'
```
assistant