Unable to open book that I created in iBooks author
I created a book in iBooks author on my mac, emailed it to myself as an iBook, and when I try opening it on my iPad 2 (which is running the most updated version of iOS7) when i got the message "unable to open book." I have tried deleting iBooks and redownloading it only to get the same message. I also sent myself a different version of the book I made and it still won't open on my iPad. Does anyone know how to resolve this issue?
iPad 2 Wi-Fi, iOS 7.0.3