/usr/bin/software-properties-gtk:TypeError:msg_reply_handler:_enabled_reply_handler:__call__:call_async

The isssue seems an incorrectly handler of error cases

'Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/dbus/connection.py", line 604, in msg_reply_handler
    reply_handler(*message.get_args_list(**get_args_opts))
  File "/usr/lib/python3/dist-packages/softwareproperties/gtk/LivepatchPage.py", line 363, in _enabled_reply_handler
    timeout=1200)
  File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 137, in __call__
    **keywords)
  File "/usr/lib/python3/dist-packages/dbus/connection.py", line 584, in call_async
    message.append(signature=signature, *args)
TypeError: Expected a string or unicode object'

Looking at some of the reports their journal log have such errors

'canonical-livepatch[851]: cannot disable machine: cannot send request: Delete https://livepatch.canonical.com/api/machine-tokens: net/http: TLS handshake timeout
update-notifier.desktop[1556]: ERROR:dbus.connection:Unable to set arguments (True, None) according to signature 'bs': <class 'TypeError'>: Expected a string or unicode object'

or

'canonical-livepatch[1161]: error in livepatch check state: check-failed
canonical-livepatch[1161]: No payload available.
update-notifier.desktop[3255]: ERROR:dbus.connection:Unable to set arguments (False, None) according to signature 'bs': <class 'TypeError'>: Expected a string or unicode object'

Hello errors.ubuntu.com, or anyone else affected,

Accepted software-properties into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/software-properties/0.96.24.32.9 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

This bug was fixed in the package software-properties - 0.98.3

---------------
software-properties (0.98.3) eoan; urgency=medium

  * debian/control:
    - required snapd-glib 1.42 (lp: #1830353)
  * data/software-properties-drivers.desktop.in:
    - enable the "Additional Drivers" desktop entry under GNOME, having it
      in "software sources" is not logical (lp: #1710377)

  [ Iain Lane ]
  * softwareproperties/gtk/LivepatchPage.py:
    - livepatch: Always pass a string to SetLivePatchEnabled (lp: #1830348)

 -- Sebastien Bacher <email address hidden> Fri, 24 May 2019 15:20:34 +0200

Using 0.96.24.32.9 shows no problem, the fix makes sense and e.u.c has no report, marking as verified

The verification of the Stable Release Update for software-properties has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

This bug was fixed in the package software-properties - 0.96.24.32.9

---------------
software-properties (0.96.24.32.9) bionic; urgency=medium

  * debian/control:
    - required snapd-glib 1.42 (lp: #1830353)

  [ Iain Lane ]
  * softwareproperties/gtk/LivepatchPage.py:
    - livepatch: Always pass a string to SetLivePatchEnabled (lp: #1830348)

  [ Corey Bryant ]
  * cloudarchive: Enable support for the Train Ubuntu Cloud Archive on
    18.04 (LP: #1829017).

 -- Sebastien Bacher <email address hidden> Fri, 24 May 2019 17:03:01 +0200