I — DO — NOT — BELIEVE — IT !!!
How simple can solutions be? I went through the parameters column again (where I thought I had only used it for restricting the image sizes) and found a “30” in a field of the type “geopoint”.
It has been there for ages (at least I found it in a long abandoned version of mid last year) and only now it started to cause trouble. So maybe others experience the same issue. Solution: just delete the wrong entry!
