Internal Server Error

The server has either erred or is incapable of performing the requested operation.

Traceback (most recent call last):
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/25fef2553b936881/python27/python27_lib/versions/third_party/webapp2-2.5.2/webapp2.py", line 1535, in __call__
    rv = self.handle_exception(request, response, e)
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/25fef2553b936881/python27/python27_lib/versions/third_party/webapp2-2.5.2/webapp2.py", line 1529, in __call__
    rv = self.router.dispatch(request, response)
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/25fef2553b936881/python27/python27_lib/versions/third_party/webapp2-2.5.2/webapp2.py", line 1278, in default_dispatcher
    return route.handler_adapter(request, response)
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/25fef2553b936881/python27/python27_lib/versions/third_party/webapp2-2.5.2/webapp2.py", line 1102, in __call__
    return handler.dispatch()
  File "/base/data/home/apps/s~infodogscouk-tipfy/3.371569571567810216/lib/app_handler.py", line 46, in dispatch
    webapp2.RequestHandler.dispatch(self)
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/25fef2553b936881/python27/python27_lib/versions/third_party/webapp2-2.5.2/webapp2.py", line 572, in dispatch
    return self.handle_exception(e, self.app.debug)
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/25fef2553b936881/python27/python27_lib/versions/third_party/webapp2-2.5.2/webapp2.py", line 570, in dispatch
    return method(*args, **kwargs)
  File "/base/data/home/apps/s~infodogscouk-tipfy/3.371569571567810216/zapps/dog_breeds/handlers.py", line 108, in get
    br_keys = [ndb_model.Key('Breeds', id) for id in json.loads(db_country.breed_list)]
AttributeError: 'NoneType' object has no attribute 'breed_list'