My Adobe ID problem is now solved! After some initial delays in getting back to me, tech support has been very responsive since yesterday. The problem, which some of you may eventually run into given how we live these days, was that I basically read/work with Adobe ID-protected content on too many devices. I read mostly on my eDGe, but also have three desktops at home and another at work (plus a phone) that I sometimes use for reading or transferring content.

Adobe IDs can only be used on six devices, which is what I was using, but when I reregistered my eDGe in an attempt to solve another (small) problem, Adobe thought I was registering a seventh device and cut me off entirely. Tech support suggested I ask Adobe for another one (after some prodding, they gave me four) and my problem disappeared.

I'm now happily reading the second half of The Black Swan (Nassim Nicholas Taleb).

Addendum: Per Adobe, in Adobe Digital Editions, Ctrl+Shift+D (Windows) or Cmd+Shift+D (Mac) will remove the activation on your computer, and allow you to reactivate with a different ID or the same ID when you launch Adobe Digital Edition again.