Rails 4 - Using namespaced STI models with devise - ruby-on-rails

Question

My rails app has 5 user models that extend User. All of which have the namespace User::UserTypeHere. When I attempt to logout of my application, devise tries to access the models as if they belong to the top level namespace, and I get the following error:
"The single-table inheritance mechanism failed to locate the subclass: 'SuperUser'. This error is raised because the column 'type' is reserved for storing the class in case of inheritance..."
How do I set up my routes in a way that devise will recognize my namespaced models?
routes.rb snippet
...
devise_for :users, skip: [:sessions, :passwords, :confirmations, :registrations, :unlocks]
devise_scope :user do
# authentication
unauthenticated :user do
root to: 'users/devise/sessions#new', as: 'new_user_session'
end
authenticated :user do
root to: 'application#index'
end
get '/login', to: 'users/devise/sessions#new', as: 'user_login_view'
post '/login', to: 'users/devise/sessions#create', as: 'user_session'
get '/logout', to: 'users/devise/sessions#destroy', as: 'destroy_user_session'
# registrations
get '/join', to: 'users/registrations#new', as: 'new_user_registration'
post '/join', to: 'users/registrations#create', as: 'user_registration'
# user accounts
scope '/account' do
# confirmation
get '/verification', to: 'users/confirmations#verification_sent', as: 'user_verification_sent'
get '/confirm', to: 'users/confirmations#show', as: 'user_confirmation'
get '/confirm/resend', to: 'users/confirmations#new', as: 'new_user_confirmation'
post '/confirm', to: 'users/confirmations#create'
# passwords
get '/reset-password', to: 'users/passwords#new', as: 'new_user_password'
get '/reset-password/change', to: 'users/passwords#edit', as: 'edit_user_password'
put '/reset-password', to: 'users/passwords#update', as: 'user_password'
post '/reset-password', to: 'users/passwords#create'
# unlocks
post '/unlock', to: 'users/unlocks#create', as: 'user_unlock'
get '/unlock/new', to: 'users/unlocks#new', as: 'new_user_unlock'
get '/unlock', to: 'users/unlocks#show'
# settings & cancellation
# get '/cancel', to: 'users/registrations#cancel', as: 'cancel_user_registration'
# get '/settings', to: 'users/registrations#edit', as: 'edit_user_registration'
# put '/settings', to: 'users/registrations#update'
# account deletion
# delete '', to: 'users/registrations#destroy'
end
end
...
user.rb (model)
class User < ActiveRecord::Base
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
end
users/super_user.rb (model)
class Users::SuperUser < User
...
end
users/devise/sessions_controller.rb
class Users::Devise::SessionsController < Devise::SessionsController
...
end

Answer 1

The value of the type column for your users needs to be Users::SuperUser, instead of just SuperUser, so that Rails autoload can find the correct class path.
Also, remember to restart your rails console & server when changing classes around, and don't keep old user instances with wrong values for type, as that will force rails to trigger an error when finding them