Since 2015, the authors of the WordPress software that many BiCon websites have used have decided that they know best what long-time users want and insisted on making a completely different way of designing and editing webpages the default. (It doesn't work at well if you're trying to edit a page on a mobile or a low powered PC, for example, but who cares about them?)
For nearly all of the BiCon sites, not enough has been broken by these 'upgrades' to change how they look.
This one's the exception and, in part because the theme that it used hasn't been updated since the switch to the new official ways of doing things, the menus stopped working. The content was still there.. you just couldn't see any sign of it. (As the person who had to make it actually work back then, it always was rather fragile but the person in charge of the visual aspects rightly liked it a lot.)
So, reluctantly, I have changed the theme. It doesn't look as nice as the original:
.. but if I find an easy way to get it looking like that again, I'll do so.