Text disappears after file format updated

I tried to open a project I last updated middle 2015 and received the following message:

The project you are trying to load uses an older file format and cannot be opened. Would you like to update? A copy of the old project will be saved in the same directory.

Fine, I let it update and it opened the project. All the folders are there, the text pages are there and labeled, but there isn’t any text on any page in the project. I keep older versions of Scriv files, so I made a copy of one and tried again with the same results. I tried other files with different text, same. I did find one that retained some of the text files, but I still lost ten chapters. I went through the folders to see if I could access the copy it backed up, but it gives the same error if I try to open it.

First: can I get the text back?
Second: how do I prevent this from happening on other files? I sometimes start writing something, then set it aside for a month or two. Or I finish a manuscript, then shelf it for several months before coming back to revise it.

This has happened to me also. Until I saw your post, I had been blaming it on something else, but now I’m wondering, like you, if this is related to the update

I received a reply from tech support a couple of days ago (for others in this situation) and here’s what they said:

I checked for double binder files and that isn’t the problem. However, I keep backup copies on a USB of all my writing, and I had another copy of the same files. I copied the files from my USB to my PC and tried it, and I was able to keep all my text. FYI, I immediately compiled and saved the sucker, just in case. So I didn’t bother to send him the file because I figured it might be a problem with the copying and transferring the originals to Dropbox, although I’d never had problems in the past.

If nothing else, this reminded me that no system is infallible, and make regular copies. I did that by making periodic copies of the scriv file, but in the future I’ll also compile it and keep progress copies that way.