Ju Ping, The problem appears to be that you have non-standard unity packages with version: 5.12+bzr2352ubuntu0+700 when they should be version: 5.12-0ubuntu1 as shown here: https://launchpad.net/ubuntu/+source/unity
To fix the problem, please run 'software-properties-gtk' and untick all non-standard (non-Canonical or non-Ubuntu) entries in 'Other Software'. After that, you should be able to force the correct versions to install with this command: sudo apt-get install libunity-core-5.0-5/precise unity/precise unity-common/precise unity-services/precise -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/996654 Title: Unity 5.12 not loading after upgrade (compiz/libunityshell.so: undefined symbol: _ZNK5unity4dash10Controller6windowEv) To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/996654/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs