This comes from an old python packet installed with python: You can solve this problem as follows:
markus@markus-desktop:~$ sudo pip3 uninstall click [sudo] password for markus: Uninstalling click: /usr/local/lib/python3.4/dist-packages/click-2.5-py3.4.egg Proceed (y/n)? y Successfully uninstalled click markus@markus-desktop:~$ -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to click in Ubuntu. https://bugs.launchpad.net/bugs/1386354 Title: package click 0.4.21.1 failed to install/upgrade: subprocess new pre- removal script returned error exit status 1 Status in click package in Ubuntu: Confirmed Bug description: While upgrading to 14.10 this continually triggers warnings I only partially understand. Now all menu-bars and side-bars are missing, though icons remain. I have booted using several kernel via GRUB menu in an attempt to avoid the problem. Also tried to install via 'sudo apt-get click --upgrade' Error message is "cannot import name 'commands'" NVIDIA proprietary driver install happened in here somewhere... 343.22 and 340.?? were tried. This restored desktop without menu bars or side-bar - the current situation. ProblemType: Package DistroRelease: Ubuntu 14.10 Package: click 0.4.21.1 ProcVersionSignature: Ubuntu 3.13.0-38.65-generic 3.13.11.8 Uname: Linux 3.13.0-38-generic x86_64 NonfreeKernelModules: nvidia ApportVersion: 2.14.7-0ubuntu8 Architecture: amd64 Date: Mon Oct 27 12:49:59 2014 DuplicateSignature: package:click:0.4.21.1:subprocess new pre-removal script returned error exit status 1 ErrorMessage: subprocess new pre-removal script returned error exit status 1 InstallationDate: Installed on 2014-03-31 (209 days ago) InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1) SourcePackage: click Title: package click 0.4.21.1 failed to install/upgrade: subprocess new pre-removal script returned error exit status 1 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/click/+bug/1386354/+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