Rails(gem Devise): Registration issue?

Question

Ruby on Rails

There is the following error:

And the following output code:

<h2>Sign up</h2>

<%= form_for(:user, :as => :user, :url => registration_path(resource_name)) do |f| %>
  <%= devise_error_messages! %>

  <div><%= f.label :username %><br />
  <%= f.text_field :username %></div>
    <br>
  <div><%= f.label :email %><br />
  <%= f.email_field :email %></div>
    <br>
  <div><%= f.label :password %><br />
  <%= f.password_field :password %></div>
    <br>
  <div><%= f.label :password_confirmation %><br />
  <%= f.password_field :password_confirmation %></div>
    <br>
  <div><%= f.submit "Sign up" %></div>
<% end %>

<%= render "devise/shared/links" %>

<br>

<pre>
  <%= params.inspect %>

I have no idea what (this time) could be the problem.
It's probably some little thing.

Answer 1

If rails version 4 is it worth updating devise to support strong_paramteres?

Answer 2

What version of Devise?