Thank you Vero for your help!
This is not a new Mac. I did install an upgrade to the MacOS last night, and as a result had to restart the computer, which I hadn't done in a few days.
The Dropbox/Alfred folder does not exist and it is not in the Dropbox trash (or my Mac trash). I use Dropbox extensively and can ensure I did not move this folder anywhere.
That is true, but when I log on to Dropbox.com I also don't see the Alfred folder. I just spent some time with Dropbox help in live chat and they don't see it either.