Why does event.ack() give SkypeApiException?

[mihalt]

When I get SkypeMessageEvent I have error like this SkypeApiException ('404 response from POST https://azeus1-client-s.gateway.messenger.live.com/v1/users/ME/conversations/ALL/messages/1737966460884/ack', <Response [404]>) on event.ack() place

My code is

    def onEvent(self, event):
        if isinstance(event, SkypeMessageEvent):
            with self.resending_appeared:
                msg = event.msg
                try:
                    self.request_save_message(msg, msg.chatId)
                except Exception as error:
                    logging.error(f"Error happened in the skype loop {error}")
                    self.error_in_thread = sys.exc_info()
                finally:
                    event.ack()
                    self.resending_appeared.notify_all()

logging.error doesn't return anything, so exception wasn't happened.