I have similar problem with flashplugin-installer and ttf-mscorefonts- installer packages:
flashplugin-installer: processing... flashplugin-installer: downloading http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_20161026.1.orig.tar.gz Get:1 http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_20161026.1.orig.tar.gz [27,2 MB] Fetched 27,2 MB in 25s (1.085 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/adobe-flashplugin_20161026.1.orig.tar.gz' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) Installing from local file /var/lib/update-notifier/package-data-downloads/partial/adobe-flashplugin_20161026.1.orig.tar.gz Flash Plugin installed. ttf-mscorefonts-installer: processing... ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/andale32.exe Get:1 http://downloads.sourceforge.net/corefonts/andale32.exe [198 kB] Fetched 198 kB in 2s (96,3 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/andale32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/arial32.exe Get:1 http://downloads.sourceforge.net/corefonts/arial32.exe [554 kB] Fetched 554 kB in 2s (248 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/arial32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/arialb32.exe Get:1 http://downloads.sourceforge.net/corefonts/arialb32.exe [168 kB] Fetched 168 kB in 2s (71,9 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/arialb32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/comic32.exe Get:1 http://downloads.sourceforge.net/corefonts/comic32.exe [246 kB] Fetched 246 kB in 2s (95,3 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/comic32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/courie32.exe Get:1 http://downloads.sourceforge.net/corefonts/courie32.exe [646 kB] Fetched 646 kB in 2s (273 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/courie32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/georgi32.exe Get:1 http://downloads.sourceforge.net/corefonts/georgi32.exe [392 kB] Fetched 392 kB in 1s (233 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/georgi32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/impact32.exe Get:1 http://downloads.sourceforge.net/corefonts/impact32.exe [173 kB] Fetched 173 kB in 1s (125 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/impact32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/times32.exe Get:1 http://downloads.sourceforge.net/corefonts/times32.exe [662 kB] Fetched 662 kB in 2s (314 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/times32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/trebuc32.exe Get:1 http://downloads.sourceforge.net/corefonts/trebuc32.exe [357 kB] Fetched 357 kB in 1s (212 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/trebuc32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/verdan32.exe Get:1 http://downloads.sourceforge.net/corefonts/verdan32.exe [352 kB] Fetched 352 kB in 1s (248 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/verdan32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/webdin32.exe Get:1 http://downloads.sourceforge.net/corefonts/webdin32.exe [185 kB] Fetched 185 kB in 1s (137 kB/s) W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/webdin32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) File permissions: # find /var/lib/update-notifier/package-data-downloads/ -ls 9052762 4 drwxr-xr-x 3 root root 4096 nov 4 10:30 /var/lib/update-notifier/package-data-downloads/ 9047630 0 -rw-r--r-- 1 root root 0 nov 4 10:30 /var/lib/update-notifier/package-data-downloads/flashplugin-installer 9078917 0 -rw-r--r-- 1 root root 0 nov 4 10:27 /var/lib/update-notifier/package-data-downloads/ttf-mscorefonts-installer 9052766 4 drwxr-xr-x 2 root root 4096 nov 4 10:30 /var/lib/update-notifier/package-data-downloads/partial -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to apt in Ubuntu. https://bugs.launchpad.net/bugs/1522675 Title: Can't drop privileges for downloading : _apt user not allowed Status in apt package in Ubuntu: Confirmed Status in dpkg package in Ubuntu: Confirmed Status in synaptic package in Debian: New Bug description: Recently we got new versions for synaptic 0.82+build1 & apt 1.1.3, but now get that error when installing/upgrading some packages: Setting up libc6-dbg:amd64 (2.21-0ubuntu5) ... Processing triggers for libc-bin (2.21-0ubuntu5) ... W: Can't drop privileges for downloading as file '/root/.synaptic/tmp//tmp_cl' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) From nautilus, i'm seeing a /root/ folder locked (x on its icon) and the folder is empty (no /.synaptic/ sub-folder or file), so the above error. oem@u64:~$ ls -l .synaptic total 4 -rw-rw-r-- 1 oem oem 0 Aug 25 11:19 options -rw-rw-r-- 1 oem oem 236 Aug 25 11:19 synaptic.conf oem@u64:~$ ls -l /var/lib/apt/lists/ .... -rw-r----- 1 root root 0 Sep 20 06:36 lock drwx------ 2 _apt root 16384 Sep 24 15:25 partial ...... oem@u64:~$ sudo ls -l /var/lib/update-notifier/package-data-downloads/ ..... drwxr-xr-x 2 _apt root 4096 Sep 22 23:33 partial ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: synaptic 0.82+build1 ProcVersionSignature: Ubuntu 4.3.0-1.10-generic 4.3.0 Uname: Linux 4.3.0-1-generic x86_64 NonfreeKernelModules: nvidia ApportVersion: 2.19.2-0ubuntu8 Architecture: amd64 CurrentDesktop: GNOME Date: Fri Dec 4 05:23:25 2015 SourcePackage: synaptic UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/1522675/+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