calibre does not start up

[Alex Onic]

When starting from the terminal, a Python error message is shown and nothing happens:
user@sys:~$ calibre
Traceback (most recent call last):
  File "/usr/bin/calibre", line 20, in <module>
    sys.exit(calibre())
  File "/usr/lib/calibre/calibre/gui_launch.py", line 73, in calibre
    main(args)
  File "/usr/lib/calibre/calibre/gui2/main.py", line 543, in main
    listener = create_listener()
  File "/usr/lib/calibre/calibre/gui2/main.py", line 514, in create_listener
    return Listener(address=gui_socket_address())
  File "/usr/lib/calibre/calibre/utils/ipc/server.py", line 110, in __init__
    self._listener._unlink.cancel()
AttributeError: 'NoneType' object has no attribute 'cancel'

Steps done before this: Removed calibre package (purge) and re-installed.
Description: Ubuntu 20.04.1 LTS
Release: 20.04

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: calibre 4.99.4+dfsg+really4.12.0-1build1
ProcVersionSignature: Ubuntu 5.4.0-51.56-generic 5.4.65
Uname: Linux 5.4.0-51-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.9
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Tue Oct 20 17:09:28 2020
InstallationDate: Installed on 2020-05-13 (159 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
PackageArchitecture: all
SourcePackage: calibre
UpgradeStatus: No upgrade log present (probably fresh install)