Bristol/Brighton seems to fail/crash/close whenever active sensing is active and also sometimes when it isn't active.
Attached are some logs showing the behaviour.
Noticed that the UI fails when entering in wrong options (or at least when specifying non existant emulations).
startBristol -jack -midi seq -pro-10 or so, will cause the B3 emulation to open up (as default) and quite soon after the Brighton GUI will report 'Detected failure of the UI' and then proceed to quit.
Tiling window manager was again the culprit in this case.
Using the -ar switch stops the constant attempts that the brighton gui makes to resize the image outside of the window boundaries, thus causing the active sensing to detect a failure.
Should move ahead with .bristolrc parameter file.