I recently used Pubcoder to create a children's picture book with the read aloud and soundtrack features. Both features work properly when I export and test the ePub file. However, when attempting to publish to iBooks through iTunes Producer even after Pubcoder validates my ePub, I receive errors from iTunes Producer:
ERROR ITMS-9000: Error while parsing file 'media overlay items must be of the 'application/smil+xml'type (given type was")'.. This error occurs 26 times.
After contacting Apple about these specific errors, they sent me this:
You encountered this new upload error because one or more of the links in your book is missing text, refers to a reference that doesn’t exist, or is not formatted correctly.
I don't have any links on my pages, and assuming that the error is occurring on every single page, it seems like there's an issue with the read aloud. I tried viewing the code on each page in Pubcoder and there's no code besides the CSS Styles for the text and images on my pages. Any ideas of what might be happening?