I've been trying to get rid of the bots accessing the site, and found it's not possible. The software is hard-coded to accept bot access. The best I can do is limit what the bots can access, and that means restrictions on the Guest account. I've removed all access to all boards for Guest, nobody can access any content without first logging in, but the bot access has not stopped. According to the logs, they are all reading the Calendar, which is also disabled.

The Forum is upgraded to the latest version. There was a 30 minute window of panic when I thought I had broken the site and the site backup doing the upgrade. Frantic keyboard activity succeeded, and here we are.