The QAManagerBase does not need to be started if there are no message listeners set, that is, if messages are received with
the GetMessage methods. It is not recommended to use the GetMessage methods as well as message listeners for receiving messages.
Use one or the other of the asynchronous (message listener) or synchronous (GetMessage) models. Any calls to Start() beyond
the first without an intervening QAManagerBase.Stop() call are ignored.