Dear Ihor Somehow, I missed your mail. Sorry for that.I get updates on my emacs installation almost weekly, so I'm fairly up to date.
I think I tackled the issue.The hours.org hangs up on opening due to an #+END entry of my clock table, which I copy every week in my :LOGBOOK: blablabla :END: drawer.
groet, Lourens van der Vliet