ImportError: No module named cred.credentials

[JohnnyReggae]

I use a Raspberry Pi3 with Raspbian. System has been working very well until I ran a system update yesterday. Deluge no longer starts correctly. When starting using systemctl is appears to be running, however the port that it runs on is not active. Running the startup manually using Python I get the following error:

root@raspberrypi:~# /usr/bin/python /usr/bin/deluged -d
/usr/lib/python2.7/dist-packages/deluge/_libtorrent.py:59: RuntimeWarning: to-Python converter for boost::shared_ptr<libtorrent::alert> already registered; second conversion method ignored.
import libtorrent as lt
[ERROR ] 06:19:38 main:248 No module named cred.credentials
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/deluge/main.py", line 241, in start_daemon
Daemon(options, args)
File "/usr/lib/python2.7/dist-packages/deluge/core/daemon.py", line 144, in __init__
from deluge.core.core import Core
File "/usr/lib/python2.7/dist-packages/deluge/core/core.py", line 53, in <module>
import twisted.web.client
File "/usr/lib/python2.7/dist-packages/twisted/web/client.py", line 36, in <module>
from twisted.web.iweb import IPolicyForHTTPS, IAgentEndpointFactory
File "/usr/lib/python2.7/dist-packages/twisted/web/iweb.py", line 16, in <module>
from twisted.cred.credentials import IUsernameDigestHash
ImportError: No module named cred.credentials

My system is:
root@raspberrypi:~# uname -a
Linux raspberrypi 4.14.52-v7+ #1123 SMP Wed Jun 27 17:35:49 BST 2018 armv7l GNU/Linux

Deluge version:
root@raspberrypi:~# apt list --installed | grep delug

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

deluge-common/stable,now 1.3.13+git20161130.48cedf63-3 all [installed,automatic]
deluge-console/stable,now 1.3.13+git20161130.48cedf63-3 all [installed]
deluged/stable,now 1.3.13+git20161130.48cedf63-3 all [installed]


I have search and have found no similar error, neither on this Forum or on Google in general.

Can anyone assist ? Unfortunately I am no Python expert so I am a little lost.

[JohnnyReggae]

I have resolved the problem eventually. Not before totally messing the system up by trying to purge packages which meant that I couldn't reinstall Deluge because of some broken packages.

So I trashed the entire system and resetup with the installation I had, ran a system update. Then installed Deluge which is now working with the lastest version of Raspbian.