Hi!
Thank you for all the time you offer for this problem.
The problem still exist, but I will close this topic, because it seems that FB is the troublemaker.
They locked the “Open Graph Object Debugger” Url, because I refreshed to much … no comment ??
I rebuild my gallery, and hope the error will vanish, because it seems new pictures are not affected by this problem.
Should I find the real error, I will mail it to you.
Bye,
Christian