There are actually a whole series of errors, the first though I think is the cause of the rest:
Code:
ERROR OEBPS/content.opf - Error while parsing file: element "package" not allowed here; expected element "ns1:package" or "ns2:package" (with xmlns:ns1="http://openebook.org/namespaces/oeb-package/1.0/" xmlns:ns2="http://www.idpf.org/2007/opf")
The line in 'content.opf the error refers to:
Code:
<package version="2.0" unique-identifier="unique-identifier" xmlns="http://www/idpf.org/2007/opf" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/">
Google (and Bing) returned one search result for this error, which I think is technically called a googlewhack,
https://www.zhihu.com/question/39893155