Solved it!!!
I’m using the Lighweight Grid Column plug-in. I had eight images with class-attributes ==> 8 error lines.
First I suspected the LGC-plug-in, but it were the class-attributes to the corresponding images… deleted one ==> 7 error lines.
Deleted all class-attributes… and the error is gone! 🙂
Do you have an explanation for that beahaviour? Or at least a suspicion?
Sven