OPF dictionary - "spine is empty" error

Hello, i'm trying to convert an opf dictionary into mobi with Calibre.

I always get "spine is empty" error, but in my opf i have some spine items.

Anyway, Kindlegen correctly generates the mobi file.

Where is the mistake?

I attached the dictionary zipped folder and the calibre log

Attached Files

	test.zip (66.3 KB)
	calibre_log.txt (4.8 KB)