I've written a script that generates epubs from hand-coded html.
I keep getting the following error when validating with epubcheck:
ERROR: ./PrisonersBase.epub/content.opf: unique-identifier attribute in package element must reference an existing identifier element id
Here's the package line from the OPF file:
<package version="2.0" xmlns="http://www.idpf.org/2007/opf" unique-identifier="BookID">
And here's the only
<dc:identifier opf:scheme="Book" id="BookID">Book_00000031</dc:identifier>
And, if it's relevant, the related line from the NCX:
<meta name="dtb:uid" content="Book_00000031" />
What am I doing wrong?
I've tried making everything lower case, removing the opf:scheme line, retyping the text and saving... Hair is being plucked in fistfuls.