Hi Larry -
I did some digging through release notes, and found you cannot upgrade to 200.9 directly from 200.5 via the method you are trying (Online). There are many reasons this can occur, but it essentially means you'll have to upgrade to something lower first.
I know you mentioned that in the browser you get "Failed to fetch versions", but do you get any type of message in the mobile app? Can you select any versions?
You can perform a local upgrade, but that's going to be a bit more involved...