Addition: Here are the packages that were updated. After this update the problem appeared on my 16.04 LTE system: Log started: 2018-03-14 06:45:32 (Reading database ... 253390 files and directories currently installed.) Preparing to unpack .../python-samba_2%3a4.3.11+dfsg-0ubuntu0.16.04.13_amd64.deb ... Unpacking python-samba (2:4.3.11+dfsg-0ubuntu0.16.04.13) over (2:4.3.11+dfsg-0ubuntu0.16.04.12) ... Preparing to unpack .../samba-common-bin_2%3a4.3.11+dfsg-0ubuntu0.16.04.13_amd64.deb ... Unpacking samba-common-bin (2:4.3.11+dfsg-0ubuntu0.16.04.13) over (2:4.3.11+dfsg-0ubuntu0.16.04.12) ... Preparing to unpack .../smbclient_2%3a4.3.11+dfsg-0ubuntu0.16.04.13_amd64.deb ... Unpacking smbclient (2:4.3.11+dfsg-0ubuntu0.16.04.13) over (2:4.3.11+dfsg-0ubuntu0.16.04.12) ... Preparing to unpack .../samba-libs_2%3a4.3.11+dfsg-0ubuntu0.16.04.13_amd64.deb ... Unpacking samba-libs:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.13) over (2:4.3.11+dfsg-0ubuntu0.16.04.12) ... Preparing to unpack .../libwbclient0_2%3a4.3.11+dfsg-0ubuntu0.16.04.13_amd64.deb ... Unpacking libwbclient0:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.13) over (2:4.3.11+dfsg-0ubuntu0.16.04.12) ... Preparing to unpack .../libsmbclient_2%3a4.3.11+dfsg-0ubuntu0.16.04.13_amd64.deb ... Unpacking libsmbclient:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.13) over (2:4.3.11+dfsg-0ubuntu0.16.04.12) ... Preparing to unpack .../samba-common_2%3a4.3.11+dfsg-0ubuntu0.16.04.13_all.deb ... Unpacking samba-common (2:4.3.11+dfsg-0ubuntu0.16.04.13) over (2:4.3.11+dfsg-0ubuntu0.16.04.12) ... Preparing to unpack .../update-notifier_3.168.8_amd64.deb ... Unpacking update-notifier (3.168.8) over (3.168.7) ... Preparing to unpack .../update-notifier-common_3.168.8_all.deb ... Unpacking update-notifier-common (3.168.8) over (3.168.7) ... Preparing to unpack .../libapparmor1_2.10.95-0ubuntu2.9_amd64.deb ... Unpacking libapparmor1:amd64 (2.10.95-0ubuntu2.9) over (2.10.95-0ubuntu2.8) ... Processing triggers for man-db (2.7.5-1) ... Processing triggers for libc-bin (2.23-0ubuntu10) ... Processing triggers for hicolor-icon-theme (0.15-0ubuntu1) ... Processing triggers for gconf2 (3.2.6-3ubuntu6) ... Processing triggers for libglib2.0-0:amd64 (2.48.2-0ubuntu1) ... Setting up libapparmor1:amd64 (2.10.95-0ubuntu2.9) ... Processing triggers for libc-bin (2.23-0ubuntu10) ... (Reading database ... 253390 files and directories currently installed.) Preparing to unpack .../libgcrypt20_1.6.5-2ubuntu0.4_amd64.deb ... Unpacking libgcrypt20:amd64 (1.6.5-2ubuntu0.4) over (1.6.5-2ubuntu0.3) ... Processing triggers for libc-bin (2.23-0ubuntu10) ... Setting up libgcrypt20:amd64 (1.6.5-2ubuntu0.4) ... Processing triggers for libc-bin (2.23-0ubuntu10) ... (Reading database ... 253390 files and directories currently installed.) Preparing to unpack .../libapparmor-perl_2.10.95-0ubuntu2.9_amd64.deb ... Unpacking libapparmor-perl (2.10.95-0ubuntu2.9) over (2.10.95-0ubuntu2.8) ... Preparing to unpack .../apparmor_2.10.95-0ubuntu2.9_amd64.deb ... Unpacking apparmor (2.10.95-0ubuntu2.9) over (2.10.95-0ubuntu2.8) ... Preparing to unpack .../friendly-recovery_0.2.31ubuntu1_all.deb ... Unpacking friendly-recovery (0.2.31ubuntu1) over (0.2.31) ... Preparing to unpack .../flashplugin-installer_29.0.0.113ubuntu0.16.04.1_amd64.deb ... Unpacking flashplugin-installer (29.0.0.113ubuntu0.16.04.1) over (28.0.0.161ubuntu0.16.04.1) ... Processing triggers for systemd (229-4ubuntu21.1) ... Processing triggers for ureadahead (0.100.0-19) ... ureadahead will be reprofiled on next reboot Processing triggers for man-db (2.7.5-1) ... Setting up libwbclient0:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.13) ... Setting up samba-libs:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.13) ... Setting up python-samba (2:4.3.11+dfsg-0ubuntu0.16.04.13) ... Setting up samba-common (2:4.3.11+dfsg-0ubuntu0.16.04.13) ... Setting up samba-common-bin (2:4.3.11+dfsg-0ubuntu0.16.04.13) ... Setting up libsmbclient:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.13) ... Setting up smbclient (2:4.3.11+dfsg-0ubuntu0.16.04.13) ... Setting up update-notifier-common (3.168.8) ... flashplugin-installer: processing... flashplugin-installer: downloading http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_20180313.1.orig.tar.gz Get:1 http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_20180313.1.orig.tar.gz [30.5 MB] Fetched 30.5 MB in 7s (3,828 kB/s) Installing from local file /var/lib/update-notifier/package-data-downloads/partial/adobe-flashplugin_20180313.1.orig.tar.gz Flash Plugin installed. Setting up update-notifier (3.168.8) ... Setting up libapparmor-perl (2.10.95-0ubuntu2.9) ... Setting up apparmor (2.10.95-0ubuntu2.9) ... Installing new version of config file /etc/apparmor.d/abstractions/base ... update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults Skipping profile in /etc/apparmor.d/disable: usr.bin.firefox Skipping profile in /etc/apparmor.d/disable: usr.sbin.rsyslogd Setting up friendly-recovery (0.2.31ubuntu1) ... Generating grub configuration file ... Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported. Found linux image: /boot/vmlinuz-4.13.0-36-generic Found initrd image: /boot/initrd.img-4.13.0-36-generic Found memtest86+ image: /boot/memtest86+.elf Found memtest86+ image: /boot/memtest86+.bin done Setting up flashplugin-installer (29.0.0.113ubuntu0.16.04.1) ... Processing triggers for libc-bin (2.23-0ubuntu10) ... Log ended: 2018-03-14 06:45:59 07:48:46 martin@pathfinder2:~$ ------------------ Start-Date: 2018-03-14 06:45:32 Commandline: aptdaemon role='role-commit-packages' sender=':1.561' Upgrade: friendly-recovery:amd64 (0.2.31, 0.2.31ubuntu1), python-samba:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.12, 2:4.3.11+dfsg-0ubuntu0.16.04.13), update-notifier-common:amd64 (3.168.7, 3.168.8), libwbclient0:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.12, 2:4.3.11+dfsg-0ubuntu0.16.04.13), flashplugin-installer:amd64 (28.0.0.161ubuntu0.16.04.1, 29.0.0.113ubuntu0.16.04.1), libapparmor1:amd64 (2.10.95-0ubuntu2.8, 2.10.95-0ubuntu2.9), samba-libs:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.12, 2:4.3.11+dfsg-0ubuntu0.16.04.13), libapparmor-perl:amd64 (2.10.95-0ubuntu2.8, 2.10.95-0ubuntu2.9), samba-common:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.12, 2:4.3.11+dfsg-0ubuntu0.16.04.13), libgcrypt20:amd64 (1.6.5-2ubuntu0.3, 1.6.5-2ubuntu0.4), libsmbclient:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.12, 2:4.3.11+dfsg-0ubuntu0.16.04.13), smbclient:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.12, 2:4.3.11+dfsg-0ubuntu0.16.04.13), samba-common-bin:amd64 (2:4.3.11+dfsg-0ubuntu0.16.04.12, 2:4.3.11+dfsg-0ubuntu0.16.04.13), apparmor:amd64 (2.10.95-0ubuntu2.8, 2.10.95-0ubuntu2.9), update-notifier:amd64 (3.168.7, 3.168.8) End-Date: 2018-03-14 06:45:59