I am sorry but I have to agree with this person too.

Booksmart has crashed several times on me as I work on this book. It is extremely frustrating. I am about to start trying to re-do a couple of hours work lost when I closed Booksmart. I notice there are a lot of .backup files but there seems to be no Help files on how to use them. 

I notice there is an article "Back up, move, transfer or share your BookSmart books" but its dated 2013 so it may not be relevant to Bookwrite.

I recommend the following: backup each time you start working; save as you go; when you close the book File, Close book. When you finish working with the program File, Quit. Work slowly, do not try to rush BookSmart is is fragile.

Thumbs down to Blurb. We are not your beta testers.

For what its worth, I re-did all my work, and when I closed the program the blurb file was gone again.

Bookwright is very disappointing. I do not recommend it. I just hope Blurb's Customer Support is better than their software. If it is, I will be as verbally positive as I am critical at the moment.

48 hours later and I have not heard back from their famed 24/7 support. The only response was an initial standard "send more info" which I did. Blurb clearly have abandoned supporting their customers, and I would not be surprised if the company is on its way out of business. If you decide to use Blurb or Bookwright, you are on on your own. I am on the hunt for a better publishing and printing outfit, and suggest you do as well.