Jep, same for me, reïnstalled python3-openssl and then we get this again:
root@box:~/mailinabox# ./management/ssl_certificates.py Traceback (most recent call last): File "./management/ssl_certificates.py", line 807, in <module> provision_certificates_cmdline() File "./management/ssl_certificates.py", line 450, in provision_certificates_cmdline status = provision_certificates(env, agree_to_tos_url=agree_to_tos_url, logger=my_logger, force_domains=force_domains, show_extended_problems=show_extended_problems) File "./management/ssl_certificates.py", line 337, in provision_certificates logger=my_logger) File "/usr/local/lib/python3.4/dist-packages/free_tls_certificates/client.py", line 64, in issue_certificate agree_to_tos_url, validation_method, acme_server, logger) File "/usr/local/lib/python3.4/dist-packages/free_tls_certificates/client.py", line 112, in validate_domain_ownership acme_server=acme_server) File "/usr/local/lib/python3.4/dist-packages/free_tls_certificates/client.py", line 317, in create_client client = acme.client.Client(acme_server, key) File "/usr/local/lib/python3.4/dist-packages/acme/client.py", line 69, in __init__ self.net.get(directory).json()) File "/usr/local/lib/python3.4/dist-packages/acme/client.py", line 641, in get self._send_request('GET', url, **kwargs), content_type=content_type) File "/usr/local/lib/python3.4/dist-packages/acme/client.py", line 614, in _send_request response = self.session.request(method, url, *args, **kwargs) File "/usr/local/lib/python3.4/dist-packages/requests/sessions.py", line 488, in request resp = self.send(prep, **send_kwargs) File "/usr/local/lib/python3.4/dist-packages/requests/sessions.py", line 609, in send r = adapter.send(request, **kwargs) File "/usr/local/lib/python3.4/dist-packages/requests/adapters.py", line 423, in send timeout=timeout File "/usr/local/lib/python3.4/dist-packages/requests/packages/urllib3/connectionpool.py", line 594, in urlopen chunked=chunked) File "/usr/local/lib/python3.4/dist-packages/requests/packages/urllib3/connectionpool.py", line 350, in _make_request self._validate_conn(conn) File "/usr/local/lib/python3.4/dist-packages/requests/packages/urllib3/connectionpool.py", line 835, in _validate_conn conn.connect() File "/usr/local/lib/python3.4/dist-packages/requests/packages/urllib3/connection.py", line 311, in connect cert_reqs=resolve_cert_reqs(self.cert_reqs), File "/usr/local/lib/python3.4/dist-packages/requests/packages/urllib3/util/ssl_.py", line 267, in create_urllib3_context context.set_ciphers(ciphers or DEFAULT_CIPHERS) File "/usr/local/lib/python3.4/dist-packages/requests/packages/urllib3/contrib/pyopenssl.py", line 385, in set_ciphers self._ctx.set_cipher_list(ciphers) TypeError: must be str, not bytes