After about a week of website problems, I finally got the site back up and running. Pro-tip for all you sysadmins out there, if you “fix” something, document precisely what you did, just in case you didn’t fix the problem or, in fact, made things worse. That way the next sysadmin will be able to respond when a frustrated user starts asking you to undo what the last person did.  Fortunately, I figured it out myself. Not a really big fix, but I had to restore some things I did when I first set up WordPress on this domain years and years ago. . . needless to say, not being a WordPress guru, I only had fuzzy memories of what that was. (i.e. time to RTFM.)