Wow, that was quick
Thank you for the quick answer.
Silly me, I thought the error message would have been enough, similar to
eg TPMS battery failure which immediately indicates to the
connoisseur that the battery of the sensor inside the wheel died.
In this case DNS means that calibre tried to contact a Domain Name Server (why?) which is not available, for one reason or the other, or so I thought.
I will restart the conversion to get a new log.