software-properties-gtk crashes with DBus.Error.ServiceUnknown

[Vladimir]

Ubuntu 20.04.4 LTS

software-properties-gtk crashes immediately after start
DBus.Error.ServiceUnknown

apt-cache policy software-properties-gtk
software-properties-gtk:
  Installed: 0.99.9.8
  Candidate: 0.99.9.8
  Version table:
 *** 0.99.9.8 500
        500 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
        500 http://archive.ubuntu.com/ubuntu focal-updates/main i386 Packages
        100 /var/lib/dpkg/status
     0.98.9.2 500
        500 http://archive.ubuntu.com/ubuntu focal-security/main amd64 Packages
        500 http://archive.ubuntu.com/ubuntu focal-security/main i386 Packages
     0.98.9 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
        500 http://archive.ubuntu.com/ubuntu focal/main i386 Packages

sudo software-properties-gtk
ERROR:dbus.proxies:Introspect error on :1.1625:/: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying
Traceback (most recent call last):
  File "/usr/bin/software-properties-gtk", line 100, in <module>
    app = SoftwarePropertiesGtk(datadir=options.data_dir, options=options, file=file)
  File "/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 222, in __init__
    self.backend.Reload();
  File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 72, in __call__
    return self._proxy_method(*args, **keywords)
  File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 141, in __call__
    return self._connection.call_blocking(self._named_service,
  File "/usr/lib/python3/dist-packages/dbus/connection.py", line 652, in call_blocking
    reply_message = self.send_message_with_reply_and_block(
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.ServiceUnknown: The name :1.1625 was not provided by any .service files

problem only in software-properties-gtk, software-properties-qt runs OK

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: software-properties-gtk 0.99.9.8
ProcVersionSignature: Ubuntu 5.4.0-107.121-lowlatency 5.4.174
Uname: Linux 5.4.0-107-lowlatency x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.21
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Sat Apr 9 01:02:27 2022
InstallationDate: Installed on 2019-05-18 (1056 days ago)
InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=ru_RU.UTF-8
 SHELL=/bin/bash
SourcePackage: software-properties
UpgradeStatus: No upgrade log present (probably fresh install)