Eeeek! I just discovered that there is something wrong with my DropBox connection. One partner has not seen files that I uploaded last November(!), and vice-versa more recently—OUCH!
When I visit my account at dropbox.com, everything seems okay. Furthermore, I store stuff there routinely for my own use (for example, thumbnail specimens for charts and topics), and they seem to work okay too.
Or DO they? Do others see what I see? Please take a look at the revival status chart, and post a response ASAP whether all thumbnails display.
I tried reinstalling the app and see nothing different. Next I must try the online help system. In the meantime, I can only apologize to everyone inconvenienced by this nightmare.