The File menu is available all the time. It does two useful things.
(1) If you are looking at one of the server's logs, such as the server event log, a client event log, or a client communication log, you can use the Save As command to save the log to a text file on disk.
(2) It contains the Exit command, used to stop WhiskerServer. WhiskerServer will request confirmation before closing:
If clients are connected, closing WhiskerServer will interrupt them and may screw up an experiment. Therefore, additional confirmation is requested:
If you confirm, the server will then close.