users module errors in Google App Engine
Actually not my answer, but from the OP, that didn't act on S. Lott's comment:

It works now! but I didnt change anything actually, seems like Google need time to update its database for app engine. like 20 mins.
I want to use user service of my domain in google App, but...
Is it possible to solve this problem by my side?

Traceback (most recent call last):
  File "/base/python_lib/versions/1/google/appengine/ext/webapp/__init__.py", line 501, in __call__
    handler.get(*groups)
  File "/base/data/home/apps/myapp2009/1.334081739634584397/helloworld.py", line 13, in get
    self.redirect(users.create_login_url(self.request.uri))
  File "/base/python_lib/versions/1/google/appengine/api/users.py", line 176, in create_login_url
    raise NotAllowedError
NotAllowedError