Not showing sign up error messages on devise

Question

First of all I would like to say Im a noob on rails.

My sign up page, using devise(rails), dont show errors like different passwords, it just dont create the user but also does not show the error message.

<div class="module" style="padding:15px 25px 0px 25px;">

  <div style="float:right; width:100%; padding-left:30px; border-left:1px solid #e2e2e2;">
    <%= form_for("user", :as => resource_name, :url => registration_path("user")) do |f| %>
      <p>
     Usuario: <br />
        <%= f.text_field :username, :style => "font-size:2.0em", :autocomplete => "off" %><br />
      </p>
      <p>
        Email: (apenas emails @usp.br sao aceitos) <br />
        <%= f.text_field :email, :style => "font-size:2.0em", :autocomplete => "off" %><br />
      </p>
      <p>
        Senha:<br />
        <%= f.password_field :password, :style => "font-size:2.0em", :autocomplete => "off" %><br />
      </p>
      <p>
        Confirmar senha:<br />
        <%= f.password_field :password_confirmation, :style => "font-size:2.0em", :autocomplete => "off" %><br />
      </p>
      <p><%= f.submit "Criar" %></p>
    <% end %>
  </div>
  <div class="clear"></div>
</div>

Sorry for my bad english.

Answer 1

Would be good to know what rails -v you use, and tag your question with appropriate tag, on your rails -v depends what devise -v you'll use, for the last version of devise you missed the devise error messages helper:

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