Ubuntu server 22.04 LTS

But did you install all your packages and dependencies through normal Ubuntu packages? The paths in the “deluged” traceback suggest that not all of them were, but that’s going on my old understanding that Ubuntu installs its packages as the same place as Debian: /usr/lib/python3/dist-packages/twisted, in the case of Twisted. The paths to the not-Twisted sources in that traceback point to where I would expect to see distro-packaged python libraries and applications.

Both `python` and `python3` seem to offer appropriate interactive responses, but when I try to run `deluged` it responds with:

Traceback (most recent call last):

[...]

File "/usr/local/lib/python3.10/dist-packages/twisted/internet/defer.py", line 40, in <module>
import attr
ModuleNotFoundError: No module named 'attr'

The Python module “attr" is found in the Ubuntu package “python3-attr”. It is one of the dependencies of the python3-twisted package. What is its status? Does “import attr” succeed in an interactive python 3 session?

Another app, nzbdplus, reports that it's running properly (after `apt reinstall`) but my usual pointing a browser to the web port 8080 doesn't work (connection reset).

When I run it on the console it appears to work -- despite complaining about certificates -- but won´t open for a browser on a local network

Any suggestions? Maybe the answer is obvious and I'm just overtired.

My guess would be that its connected to CherryPy (python3-cherrypy3), if by “nzbdplus” you are referring to the contents of the sabnzbdplus package. To be more specific, I would expect the python3-openssl package that it recommends to be the one most likely to cause complaints about certificates, and python3-cheroot is the actual HTTP server that it uses. The package python3-cryptography should also be checked.