If image upload fails I get nil error (Rails Paperclip)

I get this error:

undefined method `each' for nil:NilClass

Here:

<% @images.each do |image| %>

This is where I populate @images:

class Users::RegistrationsController < Devise::RegistrationsController

  def edit
    @images= Dir.glob("public/assets/images/users/#{current_user.id}/med/*")
    super
  end
  ...

I only get this error when i fail paperclip validation (as in image > 1mb)

    has_attached_file :image, {styles: { small: "24x24#", med: "100x100#", large: "200x200#" },
                  :url  => "/assets/images/users/:id/:style/:basename.:extension",
                  :path => ":rails_root/public/assets/images/users/:id/:style/:basename.:extension",
                  :default_url => "/assets/images/users/default/:style/default.png",
                  :keep_old_files => true}

    validates_attachment_content_type :image, :content_type => /\Aimage\/.*\Z/
    validates_attachment_size :image, :less_than => 1.megabytes

The thing is that I don't see how the file upload fail is supposed to be handled.