If an alert is displayed in the book panel, please try following workarounds:

1. The number of pages was changed outside ABPs.
The information available from ABPs > Tools > Get Book Info is book information added by New Blank Templates. If number of pages was changed outside ABPs (from Photoshop's Page Panel), then the information would not be updated.
If you wish to change number of pages, we would recommend to use the ABPs > Convert Book feature. The alert sign may disappear by changing back to original page number.
2. The document is created on another version.
The alert sign may disappear when book contents are replaced by "Replace Document" and saved under different book name.
3. The .psd file is modified outside book file.
If the document (.psd) file was modified outside the book file an alert sign may be displayed on items in book panel. The alert sign can be removed by clicking "Synchronize book" in the book panel option.
