Validated Epub contains errors
I have created the epub using Sigil. The epub passed validation using http://validator.idpf.org/, Epubchecker 3.0.1 and Flightcrew.
When I uploaded the file to Lulu, the following errors appears:
- The table of contents contains one or more links without text. (the iBookstore and Barnes & Noble)
- Contains invalid publication date XML. (Barnes & Noble)
- Contains invalid publisher XML. (Barnes & Noble)
How do I fix these errors?