I had a crash of my Mac right in the middle of saving a Pages document I was working on. It turned out that SSD broke. I had the computer repaired, the SSD replaced, and I have also recovered the entire computer from my last Time Machine backup (which had a previous version of the critical file, of course, backed up a day before the crash).
And everything seems to be fine, except that I cannot open the very same Pages document: when I try to open it, Pages gets stuck in the "Opening ..." dialog, showing the progress bar fully filled (100%). In addition, Finder has a difficulty showing the preview of that file - it display the contents with a very, very long delay (minutes).
I tried to remove the ...com.apple.iWork.Pages.savedState directory, as suggested in another answer, without success.