ssh from lets encrypt somehow failing - after those years..

log:

.. request failed : Web-based validation failed :

Error: couldn't get currently installed version for /opt/eff.org/certbot/venv/bin/letsencrypt: 
Traceback (most recent call last):
  File "/opt/eff.org/certbot/venv/bin/letsencrypt", line 7, in <module>
    from certbot.main import main
  File "/opt/eff.org/certbot/venv/local/lib/python2.7/site-packages/certbot/main.py", line 6, in <module>
    import logging.handlers
  File "/usr/lib/python2.7/logging/__init__.py", line 26, in <module>
    import sys, os, time, cStringIO, traceback, warnings, weakref, collections
  File "/usr/lib/python2.7/weakref.py", line 14, in <module>
    from _weakref import (
ImportError: cannot import name _remove_dead_weakref

and

DNS-based validation failed :

Error: couldn't get currently installed version for /opt/eff.org/certbot/venv/bin/letsencrypt: 
Traceback (most recent call last):
  File "/opt/eff.org/certbot/venv/bin/letsencrypt", line 7, in <module>
    from certbot.main import main
  File "/opt/eff.org/certbot/venv/local/lib/python2.7/site-packages/certbot/main.py", line 6, in <module>
    import logging.handlers
  File "/usr/lib/python2.7/logging/__init__.py", line 26, in <module>
    import sys, os, time, cStringIO, traceback, warnings, weakref, collections
  File "/usr/lib/python2.7/weakref.py", line 14, in <module>
    from _weakref import (
ImportError: cannot import name _remove_dead_weakref