Hi,
I had completed my ePub file ready for publish, when uploading on Itunes Producer. I receive below error:
1. Unable to Distribute Required Primary Asset
2. "Package "ISBN" failed schema validation."
3. "Line 16 column 15: character content of element "size" invalid; must be an integer greater than or equal to 1 at XPath /package/book/assets/asset[2]/data_file/size"
Could any one kindly help me to clear this error and submit my file
Regards,
Mustafa