You pasted a HTTPS address, but the server doesn't answer to HTTPS (it is somewhat redundant when you use onion services anyway). The correct one is http://scihub22266oqcxt.onion/
Of course for this kind of site that is not so important, but you shouldn't use any kind of site where you log in or enter sensitive information over Tor without HTTPS.
HTTPS is actually a bit redundant for .onion URLs, as the hostname is a representation of the host's public key.