I tried to use the Fetch News feature in Calibre to download a news source which had a RSS feed. The download job finished quickly, but the generated ebook had no pages, but had this error:
Traceback (most recent call last): File "mechanize\_urllib2_fork.py", line 1236, in do_open File "http\client.py", line 1255, in request File "http\client.py", line 1301, in _send_request File "http\client.py", line 1250, in endheaders File "http\client.py", line 1010, in _send_output File "http\client.py", line 950, in send File "http\client.py", line 1424, in connect File "ssl.py", line 500, in wrap_socket File "ssl.py", line 1040, in _create File "ssl.py", line 1309, in do_handshake ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: certificate has expired (_ssl.c:1123)
The same RSS feed or webpage opened without any problem in Firefox, Chrome, Edge and Internet Explorer.
This error is apparently due to an expired root certificate from Let’s Encrypt that might be stored in your Windows.
Calibre uses the Mechanize library to create a browser object and downloads pages using that. That object uses the root certificates from Windows and so is affected by the expired root certificate. The browsers have their own certificate store and so they are unaffected.
To delete the expired certificate:
certmgr.msc. This shows the certificates in the stores on your Windows.
After this, Calibre should be able to download the news.
Tried with: Calibre 5.38