Getting 'You are not authorized to access this page.' error even for administrator role.

ability.rb

 user ||= User.new # guest user (not logged in)
      if user.has_role? 'Administrator'
        can :manage, :all
      elsif user.has_role? 'Project manager'
        can :read, Project, :id => user.projects.pluck(:id)
        can :manage, Budget
        can :assignusertoproject, Project
        can :updateuserprojectcontract, Project
        can :destroyprojectcontract, Project, :id => user.projects.pluck(:id)
        #can :read, Project, :id => Project.with_role('Project Manager', user).pluck(:id)
      end

budgets_controller.rb
---------------------------------
load_and_authorize_resource :budgets,
    :through => :projects, :class => 'Project',
    :find_by => :project_id,
    :id_param => :project_id 

link to debug from rails console......https://github.com/ryanb/cancan/wiki/Debugging-Abilities

http://stackoverflow.com/questions/7788810/cancan-gem-with-nested-resources-and-find-by