[zamana]

Same here, after trying to convert a book from epub to AZW3:

(...)
Python function terminated unexpectedly
'int' object has no attribute 'lower' (Error Code: 1)

Traceback (most recent call last):
(...)
File "site-packages\calibre\ebooks\oeb\transforms\subset.py", line 242, in <setcomp>
AttributeError: 'int' object has no attribute 'lower'

Complete error message attached.

Thanks.
Regards.