Finalizing a book with 15 chapters, each about 15 - 30 pages (total 505 pages in book). Have several different versions, in separate folders; all with same file names and book names. Recently discovered that some files in the "FINAL" folder had been overwritten with earlier versions.

Is is sporadic and I have not been able to fully duplicatie. Looks like if A/chapter1 is open and then B/chapter1 is opened, A/chapter1 is overwritten with the content from B/chapter1. Something also occurs that causes A/chapter1 to get flagged as "possibly damaged" when next opened.

I cannot tell if this occurs only when the book file is open, or if it happens every time (I don't do it often enough to track).

Book containing the overwritten files will do successful pre-flight, but consistently CRASHES indesign completely when trying to do package for print. (Crash reports submitted)

InDesign 17.2 x64, Windows 10 Home (all updates thru May 1)