Recorder's "Stop & Save" button fails to save

I’m using Gatling 2.1.4, downloaded and installed yesterday. I’ve run the BasicSimulation file, verifying the general usage and proxy information.
When I try to follow the basic tutorial and record a session, nothing gets saved. The “Stop & Save” button (identified as merely “Stop” in the tutorial) merely exits the recording session.
I tried the given items under Simulation Information: computerdatabase & BasicSimulation. This warns me that I’m going to overwrite an existing file, but does not do so.
I tried the displayed defaults: default & RecordedSession. Same result
I tried using the already-defined directory and default file name: computerdatabase & RecordedSession. Same result.

What could I be doing wrong here? I am behind a proxy server, so I’ve configured the outgoing port. Do I perhaps need to determine a listening port other than 8000? I assume that it has to be something relatively straightforward and basic, since the failure is so cleanly complete.

Thanks for any support.

Could you provide a screen capture of your recorder set up and your browser’s network set up, please?