Hi, a.l.e. Thanks for responding.
Had the same thing happen to a different file this morning. Saved it last night before going to bed, and when I came back and opened it this morning, it had reverted back to an older version of the file. Through trial and error, I've determined that the culprit might be one of the following: 1) broken dependency files in the Scribus package (libnvidia-ifr1-390, libnvidia-ifr1-390:i386, and nvidia-driver-390) that are tied to my use of a proprietary Nvidia driver, 2) something with the nightly build (currently using 1.5.6) that requires me to re-install the software or upgrade to the most recent version of Ubuntu (currently using 18.04), or 3) a bug in 1.5.6 that's related to saving large, text-dense blocks where I've used non open-source fonts, reduced the font sizes to 11pt, and used manual line spacing to fit more text on the page. Guess I should also mention that my file is also graphics-intensive. Numerous black and white photos and graphics that have alpha channels. Am wondering if my file size might be too large.
Would love to attach a file, but the problem is that none of the new lost files in question saved. I keep getting left with older versions that Scribus keeps reverting back to.
I tried re-installing the daily build, but I keep getting an error-message about the broken packages on my system mentioned before. Next, wondering if I should just do a clean install of Ubuntu.
In the meantime, I'm trying to piece together a new file using 1.4.8. Here's hoping that the stable version of Scribus will save the file. Will let you know.
Again, thanks much for getting back to me. Be blessed today.