MrMe01 wrote: > apt-cache policy is the same, and so is apt libapt-pkg5.0.
The same as what? > What can I do to rectify this? It depends on what you have installed. But generally, you have mixed two Ubuntu versions on one system, so you have to make sure to upgrade or downgrade packages so you only have packages installed from one version; and then remove the sources.list entry for the other. apt list can help you figure out which packages are wrong. In any case, this is the wrong place for this, as I mentioned before. Markus Neubauer (mn-ubuntu) wrote: > The Problem occured also using a Zentyal 5.1 community version Again, that's not the problem this bug is about, and if they want to build their distribution by mixing Ubuntu releases; again, that's not supported. -- 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/1644643 Title: apt failed to run due to link time reference error Status in apt package in Ubuntu: Incomplete Bug description: After update apt and its related library to 1.2.15 from 1.2.10ubuntu1, I get following message when I try to invoke apt: apt-get: relocation error: /usr/lib/x86_64-linux-gnu/libapt- private.so.0.0: symbol _ZlsRSoRKN3APT9PrettyPkgE, version APTPKG_5.0 not defined in file libapt-pkg.so.5.0 with link time reference 1.2.10 do not have this problem. Now I manually downgrade from 1.2.15 to 1.2.10 to solve this problem. Ubuntu release: Description: Ubuntu 16.04.1 LTS Release: 16.04 what I expect to happen: apt would show the helper message what happened instead: apt shows me the line on above To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/1644643/+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