"Es wurde versucht, eine nicht unterstützte Operation auszuführen." -> in german. I'll try to translate ...
"Tried to execute an unsupported operation."
The favorite item was newly created. I already had another item, where I had to disable PASV, but I can't edit this one either.
I know, the workaround is to switch off PASV in the toolbar, but it would be better if the favorite item would work