title: No Validation Errors with Devise
body: <p>I use Devise for my Logins. Everything works fine with one exception. If the user enters wrong or no values on the Login page nothing happended. No Error or Error Message (Login with the correct data work fine).</p>
  
  <p>I have this problem only on the /session/new page.</p>
  
  <p>This is my view</p>
  
  <pre><code>.container
  
  
  .row.text_content_top
      .alert.alert-danger
        %button.close{ type: "button", "data-dismiss" =&gt; "alert"} ×
        = devise_error_messages!
    .row.text_content_top
      .col-md-4.col-md-offset-4
        %h2 Sign in
    .row.text_content
      .col-md-4.col-md-offset-4.well
        = form_for(resource, as: resource_name, url: session_path(resource_name)) do |f|
          = devise_error_messages!
          .input-group.has-feedback
            %span.input-group-addon
              %i.fa.fa-envelope-o.fa-fw
            = f.label :email, class: 'sr-only'
            = f.email_field :email, autofocus: true, class: 'form-control', placeholder: 'E-Mail'
          .input-group.has-feedback.top-buffer-10
            %span.input-group-addon
              %i.fa.fa-key.fa-fw
            = f.label :password, class: 'sr-only'
            = f.password_field :password, autocomplete: 'off', class: 'form-control', placeholder: 'Password'
          = f.submit "Login", class: 'btn btn-success btn-large top-buffer-10'
        = link_to "Forgot your password?", new_password_path(resource_name), class: 'top-buffer-10'
  </code></pre>
  
  <p>And my model</p>
  
  <pre><code>class User &lt; ActiveRecord::Base
    has_many :orders
  
    validates :email, presence: true, uniqueness: true
  
    devise :database_authenticatable, :registerable, :recoverable, :rememberable, :trackable, :validatable, :lockable
  
  end
  </code></pre>
  
  <p>I have no code in the controller or other custom code</p>
  
  <p>Thx in advance</p>