Ruby on Rails module requires a problem

I am learning Rails 3 through some tutorials. I found the lynda.com/Kevin Skoglund Rails 3 Essential training useful. Toward the end of the course, I encounter a problem that I cannot solve, and the links were not found on the network (or on the lynda website).

There is a module position_mover (similar to act_as_list, but simpler) that I should include in the model used. But I get errors. It:

LoadError in SubjectsController#index

no such file to load -- lib/position_mover
Rails.root: C:/Programozas/work/simple_cms

Application Trace | Framework Trace | Full Trace
app/models/subject.rb:1:in `<top (required)>'
app/controllers/subjects_controller.rb:13:in `list'
app/controllers/subjects_controller.rb:8:in `index'
This error occurred while loading the following files:
lib/position_mover
Request

Parameters:

None
Show session dump

Show env dump

Response

Headers:

None

I also have access to sample files. I tried to copy the entire application, and not change the correct version of the stones, and I get the same error. The application works fine until I try to access a model where a view is required.

Model:

require 'lib/position_mover'
class Subject < ActiveRecord::Base

include PositionMover

has_many :pages
...
end

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