rflx That's a generic error, seemingly from corrupt JSON response. In network inspector, under "Fetch/XHR", these responses will not display as (red) errors, even if they contain errors or the json is corrupt ... If you click them however, you will likely see PHP warnings in the output. That "fehler" implies the JSON is broken.
If you have a link, please send to karl @ photo.gallery, although I assume this is a non-public server.
