I can confirm the same issue on Debian: upgrading from version 0.105-20 to version 0.105-21 brings the same issue.
** CVE added: https://cve.mitre.org/cgi-bin/cvename.cgi?name=2018-1116 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to policykit-1 in Ubuntu. https://bugs.launchpad.net/bugs/1782320 Title: Braille display inoperable in GUI since polkit-update Status in policykit-1 package in Ubuntu: New Bug description: $ lsb_release -rd Description: Ubuntu 18.04 LTS Release: 18.04 $ apt-cache policy brltty brltty: Installed: 5.5-4ubuntu2 Candidate: 5.5-4ubuntu2 Version table: *** 5.5-4ubuntu2 500 500 http://nl.archive.ubuntu.com/ubuntu bionic/main amd64 Packages 100 /var/lib/dpkg/status $ apt-cache policy policykit-1-gnome policykit-1-gnome: Installed: (none) Candidate: 0.105-6ubuntu2 Version table: 0.105-6ubuntu2 500 500 http://nl.archive.ubuntu.com/ubuntu bionic/main amd64 Packages Expected behavior: After a system upgrade, the braille display should function as before the upgrade. Actual behavior: Since the upgrade, the braille display only works in console mode (Ctrl+Alt+F3, -F4, etc.) In GUI mode, the display reads "Screen not in text mode". Restarting Orca (screenreader) has no effect. Restarting the system has no effect. This is the upgrade command, taken from /var/log/apt/history.log: Start-Date: 2018-07-17 07:47:02 Commandline: /usr/bin/unattended-upgrade Upgrade: libpolkit-gobject-1-0:amd64 (0.105-20, 0.105-20ubuntu0.18.04.1), libpolkit-agent-1-0:amd64 (0.105-20, 0.105-20ubuntu0.18.04.1), libpolkit-backend-1-0:amd64 (0.105-20, 0.105-20ubuntu0.18.04.1), policykit-1:amd64 (0.105-20, 0.105-20ubuntu0.18.04.1), gir1.2-polkit-1.0:amd64 (0.105-20, 0.105-20ubuntu0.18.04.1) End-Date: 2018-07-17 07:47:04 These are the error messages taken from /var/log/syslog: Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: polkit_authority_check_authorization_sync error 11: Resource temporarily unavailable. Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: brltty: polkit_authority_check_authorization_sync error 11: Resource temporarily unavailable. Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: BrlAPI connection fd=22 accepted: local <unnamed> Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: brltty: BrlAPI connection fd=22 accepted: local <unnamed> Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: polkit_authority_check_authorization_sync error 11: Resource temporarily unavailable. Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: brltty: polkit_authority_check_authorization_sync error 11: Resource temporarily unavailable. Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: BrlAPI connection fd=22 accepted: local <unnamed> Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: brltty: BrlAPI connection fd=22 accepted: local <unnamed> Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: polkit_authority_check_authorization_sync error 11: Resource temporarily unavailable. Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: brltty: polkit_authority_check_authorization_sync error 11: Resource temporarily unavailable. Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: BrlAPI connection fd=22 accepted: local <unnamed> Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: brltty: BrlAPI connection fd=22 accepted: local <unnamed> Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: polkit_authority_check_authorization_sync error 11: Resource temporarily unavailable. Jul 18 10:55:34 WaanzinsPC2 brltty[2635]: brltty: polkit_authority_check_authorization_sync error 11: Resource temporarily unavailable. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: brltty 5.5-4ubuntu2 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.2 Architecture: amd64 Date: Wed Jul 18 11:03:27 2018 ExecutablePath: /bin/brltty InstallationDate: Installed on 2018-05-15 (63 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426) LocalLibraries: /usr/local/lib/libgpg-error.so.0.24.2 /usr/local/lib/libgcrypt.so.20.2.2 SourcePackage: brltty UpgradeStatus: No upgrade log present (probably fresh install) mtime.conffile..etc.brltty.conf: 2018-05-16T09:36:35.497752 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/policykit-1/+bug/1782320/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp