Catastrophic loss of index data
Yesterday I laboriously created an index of a 60-page document. Today, half of the index entries are gone. And the IDML backup I made of the file shows all index entries as "PN," which, of course, is totally incorrect.
It appears that the file lost all index entries after page 40, yet I know they were there yesterday, since I entered them laboriously for hours on end.
This happens in my InDesign book documents sometimes, but if I synchronize the files, the index entries reappear.