That's not an error - it's just telling you it didn't find an exact match for the title on Amazon. Because of that it's assigning a fictional/random identifier in place of the ASIN.
Furthest page updates will work on multiple devices as long as all copies of the ebook have the same (real or fake) ASIN assigned on the device copy.
Lately I've been noticing Calibre assigning ASINs when updating metadata much of the time, FWIW. As long as I see a value populating the Ids / Amazon: field I'm not even bothering with the script anymore, even if it was fun debugging installing it a few months ago. Seems obsolescent to me at this point.