As the first initial release is only a few hours old, we will see if its trust worthy. I'm personally getting an error for every image of missing java environment which is properly installed.
Can you specify your errors?
- OSX Users now need to have the Java Development Kit (JDK) installed.
- ePubs, created with InDesign CC 2014.x or older versions might show the warning: WARNING(OPF-007): ./Desktop/ePub-Muster.epub/OEBPS/content.opf(2,324): Re-declaration of reserved prefix ‘rendition’. If you wish to remove this warning, open your ePub > content.opf with the editor and remove »rendition: http://www.idpf.org/vocab/rendition/# « (incl. the space at the end). This entry can be usually found on the second line.
II did get that WARNING also.
I decided to use Pagina's EPUB-Checker which I read is a good validator. And still use Epubcheck 3.0.1 to compare...
The Pagina ePub-Checker has epubcheck running under the hood. Its really a great utility and I use it also for my checks. The Developer will update the Pagina EPUB-Checker, soon as well.
Also InDesign CC 2015, the latest version, creates this problem.
The solution works: there's no warning anymore in the checker.
BUT in iBooks the epub now looks terrible.