undefined method `each_byte' for nil:NilClass

[gushonorato]

Hi, when I try to use you API I'm getting the following error: undefined method 'each_byte' for nil:NilClass when execute this method:

  def perform
    begin
      Authorization.default_role = :admin

      task = ArticleManager::ArticleWritingTask.find(article_writing_task_id)
      search = Copyscape.text_search(strip_tags(task.content))

      if search.duplicate?
        task.suspect!
      else
        task.accept!
      end

    ensure
      Authorization.default_role = :anonymous
    end
  end

This is the full stack trace:

NoMethodError (undefined method `each_byte' for nil:NilClass):
  app/jobs/article_writing_task_copyscape_job.rb:10:in `perform'
  app/models/article_manager/article_writing_task.rb:140:in `submit'
  app/controllers/article_manager/article_writing_tasks_controller.rb:49:in `block in update'
  app/controllers/article_manager/article_writing_tasks_controller.rb:46:in `update'

I'm using:

• Rails 3.1.rc5
• Ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-linux]