:-) appreciate your quick help for a beginner like me very much!
OK thanks. I obviously missed the shared option :-(
Anyway, is there any option or even workaround to bulk edit all albums in order to set them to shared?
Where are you hosting your site, 1&1? If yes there is a thing called “Safe Mode” which prevents these plugins to work properly. You need to switch to “Free Mode” and everything works as expected.