Any filed edited using v2.03 will not open on Kobo

[oberon567]

After downloading the update to the newest version (2.03), any file that I edited would not open on my Kobo Libra 2. It gave the error that I do not have the Adobe Right management authorization to access that file. I reverted to v2.01 and re-edited the metadata on the files and they worked fine on the Kobo.

[benchen71]

That's interesting. I've been getting the same error. I will definitely investigate why the changes in the latest version are causing problems.

[benchen71]

Interestingly, v2.01 didn't get rid of the error in my testing. However, running them through Calibre (converting them from EPUB to EPUB) fixed the issue. If I can find what Calibre did, I might be able to work out how to fix the issue. Definitely open to suggestions!

[oberon567]

Come to think of it, I may have had to run them through Calibre, too. Sorry I don't quite remember... It was last month this happened, then I downgraded back to 2.01 and haven't hadn't the problem since... Only today I came across another book that gave me the same error and only then did I think to come here and see if anyone else had logged the error...

At first I did open up the original and the Calibre-fied versions side-by-side (in the Calibre editor), to see if I could figure out what was going on... It was very clear that the way ePubMetaData Editor was creating meta tags was different than the Calibre versions, but that doesn't seem like something that should trigger such an error. Plus ePubMetaData Editor always, with every single ePub, says that the Cover Image is Not Prioritized.. it says that for every single ePub I have ever edited, regardless of where it comes from, but also doesn't point toward that error in any useful way... But my knowledge of the CSS/HTML that functions as the inner guts of an ePub file is more or less nonexistent, so I was just poking in the dark and it wasn't particularly effective. Sorry!

[benchen71]

You can safely ignore the "Not Prioritized" error message. (It's more of a warning anyway.) I don't recall who asked for it, but from memory, some EPUB readers back in the day would only find the cover image, if it was the first image encountered in the zip file. So the solution was to put a couple of zeros at the start of the cover filename.
When comparing a Calibre-edited file with an EPUBMetadataEditor-edited file, there are some differences at the very top of the OPF file, which I can certainly look into. But it's hard to see those differences causing problems with Kobo readers.