Chapter Number Problems
If you delete a number of chapters from a book, the chapter numbers of the others are not rebuilt. When viewing the book, its table of contents will jump in numbers. The total number of chapters is based on the highest chapter number it sees, and is not updated in this situation. This second part doesn't really cause any issues because it is masked by some other checks for other missing data for these chapters. The numbers in the database are intended to keep track of ordering and should not be used for the purposes mentioned above.
Fixed for the next build. VaultWiki will attempt to count the chapters rather than grabbing the highest number. Also, the chapter list will not use the database's chapter numbers anymore but a counter instead.