phoenix trace

gistfile1.txt

20:28:04.489 request_id=YKBV9h8rPqSKmuGDpZGs [debug] Processing by Chat.PageController.chat/2
  Parameters: %{"format" => "html"}
20:28:04.503 request_id=YKBV9h8rPqSKmuGDpZGs [debug] Processing by Phoenix.Controller.ErrorController.error_debug/2
  Parameters: %{"format" => "html"}
20:28:04.512 request_id=YKBV9h8rPqSKmuGDpZGs [error] **(Protocol.UndefinedError) protocol Enumerable not implemented for nil
    (elixir) lib/enum.ex:1: Enumerable.impl_for!/1
    (elixir) lib/enum.ex:140: Enumerable.count/1
    (elixir) lib/enum.ex:434: Enum.count/1
    (chat) web/views/page_view.ex:2: Chat.PageView.render/2
    (phoenix) lib/phoenix/view.ex:247: Phoenix.View.render_within/3
    (phoenix) lib/phoenix/view.ex:262: Phoenix.View.render_to_iodata/3
    (phoenix) lib/phoenix/controller.ex:451: Phoenix.Controller.render/4
    (chat) web/controllers/page_controller.ex:1: Chat.PageController.phoenix_controller_stack/2