Here is the tail of /var/log/syslog when I try and fail to select Canonical Partners"
Apr 23 21:52:20 mycomputer gnome-shell[1932]: pushModal: invocation of begin_modal failed Apr 23 21:52:20 mycomputer gnome-shell[1932]: polkitAuthenticationAgent: Failed to show modal dialog. Dismissing authentication request for action-id com.ubuntu.softwareproperties.applychanges cookie 2-23574a46bd8318158fe3dd4ecc52a32a-5-c93d2ab7373f92c6fc2f3db033d3eb15 Apr 23 21:52:20 mycomputer software-properties-gtk.desktop[1932]: ERROR:root:Authentication canceled, changes have not been saved Apr 23 21:52:27 mycomputer systemd[1675]: tracker-extract.service: Succeeded. Apr 23 21:52:44 mycomputer gnome-shell[1932]: pushModal: invocation of begin_modal failed Apr 23 21:52:44 mycomputer gnome-shell[1932]: polkitAuthenticationAgent: Failed to show modal dialog. Dismissing authentication request for action-id com.ubuntu.softwareproperties.applychanges cookie 2-23574a46bd8318158fe3dd4ecc52a32a-6-665483d7b8251faa59df638e0cb38a3f Apr 23 21:52:44 mycomputer software-properties-gtk.desktop[1932]: ERROR:root:Authentication canceled, changes have not been saved Apr 23 21:52:55 mycomputer gnome-shell[1932]: pushModal: invocation of begin_modal failed Apr 23 21:52:55 mycomputer gnome-shell[1932]: polkitAuthenticationAgent: Failed to show modal dialog. Dismissing authentication request for action-id com.ubuntu.softwareproperties.applychanges cookie 2-23574a46bd8318158fe3dd4ecc52a32a-7-447f164721374873942ad295e4688bff Apr 23 21:52:55 mycomputer software-properties-gtk.desktop[1932]: ERROR:root:Authentication canceled, changes have not been saved -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to software-properties in Ubuntu. https://bugs.launchpad.net/bugs/1825590 Title: "software & updates" freezes after selecting "canonical partners¨ Status in software-properties package in Ubuntu: Incomplete Bug description: On a fresh install of 19.04, in "Software & Updates" when I select "Canonical Partners" the window "Authentication Required" pops up. After typing the password the mouse freezes, and can be unfrozen with CTRL+ALT+DEL. But the "Canonical Partners" cannot be selected, check box stays empty, mouse freezes again. Even after cold restart. WORKAROUND Select "Canonical Partners Sources" instead. After authorizing I can now also select "Canonical Partners". This was impossible before. After this I can select and deselect Canonical Partner in "Software & Updates". The previous authorization window, which opened first, and when the mouse froze, stays open and cannot be closed with CANCEL or ALT+F4. ProblemType: Bug DistroRelease: Ubuntu 19.04 Package: software-properties-gtk 0.97.11 ProcVersionSignature: Ubuntu 5.0.0-13.14-generic 5.0.6 Uname: Linux 5.0.0-13-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.10-0ubuntu27 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Sat Apr 20 00:17:33 2019 ExecutablePath: /usr/bin/software-properties-gtk InstallationDate: Installed on 2019-04-19 (0 days ago) InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416) InterpreterPath: /usr/bin/python3.7 PackageArchitecture: all ProcEnviron: LANGUAGE=en_GB:en PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_GB.UTF-8 SHELL=/bin/bash Python3Details: /usr/bin/python3.7, Python 3.7.3, python3-minimal, 3.7.3-1 PythonDetails: N/A SourcePackage: software-properties UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/software-properties/+bug/1825590/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp