I am mystified because I haven't made any changes to any files on my site, haven't activated or deactivated any plugins, haven't done anything except navigate around the site, and my theme has suddenly stopped working.
When I switch to the default Buddypress theme everything seems to work, but when I activate my theme it looks as though the main style.css, which is in the same place it always is, isn't getting loaded, as the site has no styling and is completely disfigured.
You can see what I mean here.
I have tried to reverting to an old version of my theme and still see the issue, which suggests that it is not related to the content of my child theme folder.
I am completely stumped as to what is going on and would be glad of any help to get my site back up and running again. I have tried deactivating and reactivating my child theme, with no success.