I have the same error as of today, but I haven't got a mention of an update by MS. I am a bit glad I am not the only one. I did update Calibre portable to v3.31 and even tried downloading metadata on a book I have updated yesterday. This is now not working.
(Update) Error: 'Metadata download failed'. Details:
Code:
calibre, version 3.31.0
FOUT: Download mislukt: Metadata downloaden mislukt. Klik op ‘Toon details’ voor meer informatie
Traceback (most recent call last):
File "site-packages\calibre\utils\ipc\simple_worker.py", line 289, in main
File "site-packages\calibre\ebooks\metadata\sources\worker.py", line 102, in single_identify
File "site-packages\calibre\ebooks\metadata\sources\update.py", line 79, in patch_plugins
File "site-packages\calibre\ebooks\metadata\sources\update.py", line 62, in patch_search_engines
File "<string>", line 11, in <module>
ImportError: No module named polyglot.builtins