Traceback in tornado code

[cparlette]

This traceback shows up for me, I installed tornado-3.1.1 from tornadoweb.org instead of from apt-get. Nothing seems to be affected, just wanted to note it here.

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/tornado/web.py", line 1141, in _when_complete
    callback()
  File "/usr/local/lib/python2.7/dist-packages/tornado/web.py", line 1162, in _execute_method
    self._when_complete(method(*self.path_args, **self.path_kwargs),
  File "/usr/local/lib/python2.7/dist-packages/tornado/web.py", line 2297, in wrapper
    return method(self, *args, **kwargs)
  File "chodewars.py", line 88, in get
    game = game,
  File "/usr/local/lib/python2.7/dist-packages/tornado/web.py", line 538, in render
    html = self.render_string(template_name, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/tornado/web.py", line 643, in render_string
    namespace = self.get_template_namespace()
  File "/usr/local/lib/python2.7/dist-packages/tornado/web.py", line 666, in get_template_namespace
    namespace.update(self.ui)
TypeError: 'NoneType' object is not iterable

[rskumar]

I am just curious to know the cause of this error. Its bit difficult to understand error from tornado.