Dear Florian,
Thank you for your reply. When I upgraded, I started completely anew with your fresh new 3.1.6 package, i.e. also the elements folder was the new one from your ZIP. As the videos did not work, I copied my pictures into 3.1.5. - Perhaps the cache is the reason then. I will check (with the next book), whether the reason for my videos not working was, indeed, the cache, and will let you know here.
This evening, you have impressed some new people with your great work! :-) They like your Megazine very much, too.
(
http://maxie-online.de, in case you haven't seen it yet. A megazine for a MegaZine workshop. :-))
Wishing you wonderful holidays,
Maxie