When in quiesce mode, the UIMA-AS service stops its jms listeners to prevent more CASes from coming in. In a rare event when the listener is told to stop, it may actually may be reading a message from its queue. In such case, the jms listener rejects the message. This effectively results in a message loss. The listener should allow the message to be processed instead. There is an API which allows for programmatic override of the default behavior acceptMessagesWhileStopping(true/false). The UIMA-AS code should change the setting to true to allow the message while the listener is stopping.