Sorry, never seen that before but I am going to guess that there IS a hidden page in there somewhere by accident. We need to see your title. Use File > Export > Zip to save your title and post that to the Files section of the Lectora Lounge or send to me at ben.pitman@eProficiency.com. You just need to include the pages that are giving a problem so you might want to make a special version of the title by copying the folder and deleting the unnecessary pages.
