Yes, first thing I did was search for solutions. That's how I found the firewall solution... which didn't work. Thanks for the compatibility suggestion, but that also didn't help. Like I said, the really weird thing is that I've had no issue with the 23 books I've bought from Kobo since Blindsight. And even now, I'm still getting the exact same error.

e: Going to email back to Kobo support asking if they'd have someone who'd be able to take a look into the server side of things, as suggested by one of the older Adobe support threads.