Transititions gem errors

app-controller-user.rb

class UsersController < InheritedResources::Base
  belongs_to :account
  actions :all, :except => :destroy
end

app-models-account.rb

class Account < ActiveRecord::Base
  include ActiveModel::Transitions

  attr_accessible :identifier, :name, :package_id, :user_id, :status
  has_paper_trail

  belongs_to :package
  belongs_to :user
  has_many :users

  validates :name, :identifier, :package_id, presence: true
  validates :identifier, uniqueness: true
  validates :user_id, presence: true, if: "self.users.present?"

  state_machine auto_scopes: true, attribute_name: :status do
    state :active
    state :inactive

    event :deactivate do
      transitions from: :active, to: :inactive
    end

    event :activate do
      transitions from: :inactive, to: :active
    end
  end
end

app-models-user.rb

class User < ActiveRecord::Base
  include ActiveModel::Transitions

  ROLES = ['owner', 'manager', 'staff']

  attr_accessible :account_id, :email, :name, :password, :password_confirmation, :role, :status
  has_paper_trail

  belongs_to :account

  validates :name, :email, :account_id, :role, presence: true
  validates :role, inclusion: { in: ROLES }

  state_machine auto_scopes: true, attribute_name: :status do
    state :active
    state :suspended

    event :suspend do
      transitions from: :active, to: :suspended
    end

    event :activate do
      transitions from: :suspended, to: :active
    end
  end
end

Gemfile

source 'https://rubygems.org'

gem 'rails', '3.2.15'
gem 'mysql2'
gem 'bcrypt-ruby', '~> 3.0.0'
gem 'rails-settings-cached'
gem 'inherited_resources'
gem 'has_scope'
gem 'transitions', :require => ["transitions", "active_model/transitions"]
gem 'devise'
gem 'cancan'
gem 'kaminari'
gem 'simple_form'
gem 'delayed_job_active_record'
gem 'ransack'
gem 'daemons'
gem 'redcarpet'
gem 'wicked_pdf'
gem 'paper_trail', '>= 3.0.0.rc2'

group :assets do
  gem 'therubyracer', :platforms => :ruby
  gem 'sass-rails',   '~> 3.2.3'
  gem 'less-rails'
  gem 'coffee-rails', '~> 3.2.1'
  gem 'uglifier', '>= 1.0.3'
end

gem 'jquery-rails'
gem 'jquery-cookie-rails'
gem 'less-rails-bootstrap'
gem 'kaminari-bootstrap'
gem 'select2-rails'
gem 'font-awesome-rails'
gem 'bootstrap-datepicker-rails'
gem 'humane-rails'

views-users-_form.html.erb

<div class="panel">
  <%= simple_form_for @user do |f| %>
    <div class="panel-body">
      <%= f.input :name %>
    </div>

    <div class="panel-footer">
      <div class="form-group m-b-none">
        <div class="col-sm-offset-2 col-sm-10">
          <%= f.submit :class => 'btn btn-success' %>
          <%= link_to t('buttons.cancel'), @user.persisted? ? account_user_path : account_users_path, :class => 'btn btn-default' %>
        </div>
      </div>
    </div>
  <% end %>
</div>

views-users-new.html.erb

<div class="header bg-white-only b-b">
  <h4 class="pull-left"><%= t '.title' %></h4>

  <div class="btn-group pull-right">
    <%= link_to t('buttons.accounts.view'), account_path(@account), :class => 'btn btn-success btn-sm' %>
    <%= link_to t('buttons.users.all'), account_users_path(@account), :class => 'btn btn-success btn-sm' %>
  </div>

  <div class="clearfix"></div>
</div>

<div class="wrapper">
  <%= render 'form' %>
</div>