That's really strange, after working again for a few days Okular
suddenly stopped starting again. Out of nowhere. I had some PDFs open
(recently opened ones, and some opened a few days ago). After closing
some of them, I wasn't able to start new Okular sessions.
I can't really say how to reproduce this, and I'm not able to get any
helpful debug output. Seems like a Higgs-Bugson[1] or Bugfoot[2] to me... ;)
[1]: http://www.codinghorror.com/blog/2012/07/new-programming-jargon.html
[2]: http://www.urbandictionary.com/define.php?term=bugfoot