Just a warning: this bug is the prime suspect in an application failing after 55 days continuous use. LabVIEW has a limit of one million Queues alive at any time, after which "Obtain Queue" throws an Error 2: out of memory. This happens after 55 days if one actor shuts down (without its Caller shutting down) every 5 or so seconds. Unfortunately the application was built two days before this bug was reported. Please upgrade to the latest Messenger Library version.