One of my routes is not working

I have a User model which has_many :portfolios and each Portfolio
:pictures. My routes look like this:

resources :users do
resources :portfolios do
resources :pictures

Then I try to create a new Portfolio like this:

<%= link_to “new portfolio…”, new_user_portfolio_path(current_user) %>

With a form like this:

<%= form_for [current_user, @portfolio], html: { class: “form_settings”
} do |f| %>…<% end %>

But when I click on “new portfolio…” my URL says
/users/12/portfolios/new and I get this error:

No route matches {:action=>“show”, :controller=>“portfolios”,
:user_id=><User id: 12, name: “michael”, password_digest:
“d787f56b080945c1ec0b3343cbf962ca427bb8ef”, remember_token:
“dL4nPlt0E5azUMemNIvkdg”, admin: false, created_at: “2013-03-03
01:18:19”, updated_at: “2013-03-03 19:56:28”>, :id=><Portfolio id: nil,
user_id: 12, name: nil, created_at: nil, updated_at: nil>}