No, it still does not work... I suppressed the file intrface.bbw, but BiaB produced immediately a new one after having asked whether I want BiaB open .MGU files.
Opening BiaB, setting customs tabs, closing, reopening BiaB, custom tabs gone!
I run BiaB 2017 with patch 253.
I suppose re-inserting the old intrface.bbw (which I have kept aside) cannot solve the problem as it was not working before....
Bernard