[DaySleeper]

Post edited because I found the solution to the problem (I could see my Calibre library from Moon+Reader after both computer & tablet were updated, but couldn't download books). I discovered that in the more current versions of Moon+Reader and/or Calibre, the two connect better if instead of just entering the displayed IP address on the content server into Moon+Reader, you need to add a new connection, at which point Moon+Reader provides "local Calibre server" as an option. Using that, and entering the correct ip address, restores the functionality I had in my previous installations with a more manual setup.

I didn't find a way to just delete this post, so now instead of a request for help it describes the solution - hopefully someone else will find it helpful.