ps - As I typed the above, I realized that my radio station location had a router failure at about the same time. We lost the internet, including out studio/transmitter link. I bet that has to do with the problem.
The router failure indeed did cause the problems. Later that night, I did do memory stick backup of Firefox's bookmark file, but could not get to where the login/password information is. I do have paper records of all those, but thankfully didn't need to go that route, because...
A couple of nights later, Firefox did another update and fixed all the problems.
I have now done what I should have done many years ago - I put all the download links, logins, and passwords in Firefox on another computer at the radio station. But at that other computer, the downloads will need to be sneaker-netted to the stations programming server network. With the exception of my backroom download computer, none of the station's computers are connected to both station networks. Don't want people to bung up the program operations computers by them accessing the internet with them.
VERY glad I didn't have to uninstall/reinstall Firefox.
Moose