Cannot import name _remove_dead_weakref Ubuntu 14.04.4

#1

after the last update I saw this line in the logs:
/opt/eff.org/certbot/venv/local/lib/python2.7/site-packages/cryptography/hazmat/primitives/constant_time.py:26: CryptographyDeprecationWarning: Support for your Python version is deprecated. The next version of cryptography will remove support. Please upgrade to a 2.7.x release that supports hmac.compare_digest as soon as possible.

then update all
and no longer starts

I run this command:
/root/letsencrypt/letsencrypt-auto renew --force-renewal && /etc/init.d/apache2 reload

It produced this output:

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
from certbot.main import main
File “/opt/eff.org/certbot/venv/local/lib/python2.7/site-packages/certbot/main.py”, line 5, in
import logging.handlers
File “/usr/lib/python2.7/logging/init.py”, line 26, in
import sys, os, time, cStringIO, traceback, warnings, weakref, collections
File “/usr/lib/python2.7/weakref.py”, line 14, in
from _weakref import (
ImportError: cannot import name _remove_dead_weakref

My web server is (include version):
apache 2.4.38

The operating system my web server runs on is (include version):
Ubuntu Linux 14.04.4

I can login to a root shell on my machine (yes):

#2

The main problem is this version is no long supported:

See: https://wiki.ubuntu.com/Releases

You may need to upgrade that to a new release to continue to get all the latest packages.

#3

It’s still supported for the next couple weeks.

_weakref is a built-in module, it shouldn’t possibly be able to malfunction.

Maybe rename or delete /opt/eff.org/certbot to reinstall Certbot and rebuild the Python virtualenv?

#4

14.04.6, yes.

but not 14.04.4:
image