Common error messages
- Error while parsing file 'attribute "value" not allowed here; expected attribute "class", "dir", "id", "lang", "style", "title" or "xml:lang"
- The copyright page is missing.
- The generated Table of contents is incorrect with a "start" tag.
- Error while parsing file 'value of attribute "id" is invalid'
- Embedded cover not found or can't be identified.
- Cover image is too large: can't be larger than 4 megapixels