Seems that I missed something and when we upgraded docker, I lost the docker image which was running the mysql DB which contained the man pages on our legacy site.
So, I fixed this error today and the man pages are all up and running again on the legacy site.
See, the docker upgrade which caused this error...
I think I need to take some time off other volunteer and charity projects and make changes to the legacy site.
www.unix.com $ uptime
08:58:14 up 1674 days, 1:18, 3 users, load average: 4.73, 5.30, 4.56
1674 days is approximately 4.59 years, which is a long time without a reboot!
If I am not mistaken, the DB which drives the man pages over there was down for about two weeks after I made the docker upgrade to this site. I forgot there was a mysql docker container running the man pages and for some reason, that image was lost during the upgrade process.