Rails: DoubleRenderError - "Render and/or redirect were called multiple times in this action"

You shouldn't return redirect_to in the after_sign_in_path_for. You should return url:

  def after_sign_in_path_for(user)
     if current_user.role_ids == [2]
       return workers_url
     else
       return tasksadmins_url
     end
  end