It looks like your application doesn't have a rule for /admin/
. You'll need to change your application
to this:
application = webapp2.WSGIApplication([
('/admin/', AdminPage),
], debug=True)
When you go to /admin/
, the login: admin
part of your app.yaml
shows the login error before it ever hits your admin.py
file if you're not logged in. When you are logged in, the application tries to find a url matching /admin/
, but the only configured url is /
.