im pretty sure it came up it again recently for me.
Note it is only a specific case where you have downloaded a new version.
You get the download ready for offline message then maybe shut down close up with the idea that next time you will be off line.
But then later, when you are off line, you go to preview, or debug preview, and it will not work.
I have found the way to get around it, is, once I see the downloaded message, then run a blank preview and a blank debug while on line, and then go off line.
Then they will work off line later. but if you dont pre run the previews on a new version while on line they wont subsequently work off line. The issue is separate for both preview and debug.
is there maybe something happening out in the wild that is not occurring in your development environment?