Hi Pankaj , yes you were right! The problem was that I released my domains for viewing on friends.hapkido-magazin.de at Vimeo. That seems to enable the incorporation of videos on my site, but not at the same time to query thumbnails that are actually available. I will probably have to ask Vimeo how this can be solved, because I need the films to be restricted to our magazine page, because they cannot be integrated on other pages due to the copyright.
I recognized the error when I released Jomsocial.com as a domain at Vimeo and even the demo of Jomsocial showed the error. Only the approval for all domains allowed a preview picture to be created. If I restrict the setting at Vimeo after creating the preview image, the image will still be displayed. I can live with that!
In the meantime, thanks to this forum, I was able to solve a few errors without your direct support, so I allow myself to post my solution for others here.
