When the mobile is in a vertical orientation, the next page is displayed by scrolling down. When the device is in landscape orientation, the next page is displayed by scrolling from right to left. If it is a notebook, check to see if you have reached its last page. Open the next chapter from the contents menu. In any other case, exit the book or notebook and tap the Publior icon to refresh your screen. If the malfunction continues, you can perform the Forced Stop procedure on your device and try again.