I prepared my 8th book in the book module and was nearly ready to upload. I closed LR CC 10.11 and reopened it the next day and wenated to continue my book. 2 out of 3 books where OK but in one I do see the pages and the places I initially inserted the images, but all references are gone. I can't see any images in the book anymore and the counter showed on top of each image also disappeared. So all the work is lost.