IndexError

IndexError: list index out of range
Traceback (most recent call last)

    File "C:\Python27\lib\site-packages\flask\app.py", line 2000, in __call__

    return self.wsgi_app(environ, start_response)

    File "C:\Python27\lib\site-packages\flask\app.py", line 1991, in wsgi_app

    response = self.make_response(self.handle_exception(e))

    File "C:\Python27\lib\site-packages\flask\app.py", line 1567, in handle_exception

    reraise(exc_type, exc_value, tb)

    File "C:\Python27\lib\site-packages\flask\app.py", line 1988, in wsgi_app

    response = self.full_dispatch_request()

    File "C:\Python27\lib\site-packages\flask\app.py", line 1641, in full_dispatch_request

    rv = self.handle_user_exception(e)

    File "C:\Python27\lib\site-packages\flask\app.py", line 1544, in handle_user_exception

    reraise(exc_type, exc_value, tb)

    File "C:\Python27\lib\site-packages\flask\app.py", line 1639, in full_dispatch_request

    rv = self.dispatch_request()

    File "C:\Python27\lib\site-packages\flask\app.py", line 1625, in dispatch_request

    return self.view_functions[rule.endpoint](**req.view_args)

    File "C:\PokeyPyManager-master\pogo\mgr.py", line 75, in release

    logging.critical(session.releasePokemon(inventory.party[poke]))

    File "C:\PokeyPyManager-master\pogo\session.py", line 302, in releasePokemon

    self._state.release.ParseFromString(res.returns[0])

    File "C:\Python27\lib\site-packages\google\protobuf\internal\containers.py", line 204, in __getitem__

    return self._values[key]

    IndexError: list index out of range