Public bug reported: I got the error after installing below package. gnome-session-fallback
ProblemType: Package DistroRelease: Ubuntu 14.04 Package: libapt-inst1.5:amd64 1.0.1ubuntu2.14 ProcVersionSignature: Ubuntu 4.2.0-27.32~14.04.1-generic 4.2.8-ckt1 Uname: Linux 4.2.0-27-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.14.1-0ubuntu3.21 AptdaemonVersion: 1.1.1-1ubuntu5.2 Architecture: amd64 CrashReports: 640:0:116:1872888:2016-06-11 13:17:19.952006340 +0530:2016-06-11 13:17:23.656006520 +0530:/var/crash/libtasn1-6:amd64.0.crash 600:0:116:210370:2016-06-11 04:05:34.114207029 +0530:2016-06-11 04:05:35.114207029 +0530:/var/crash/libexpat1:amd64.0.crash 600:0:116:210377:2016-06-11 04:05:34.098206996 +0530:2016-06-11 04:05:35.098206996 +0530:/var/crash/libapt-inst1.5:amd64.0.crash 600:109:116:0:2016-06-11 13:17:25.912006600 +0530:2016-06-11 13:17:25.912006600 +0530:/var/crash/libtasn1-6:amd64.0.uploaded 644:0:116:0:2016-06-11 13:17:22.632006483 +0530:2016-06-11 13:17:22.632006483 +0530:/var/crash/libtasn1-6:amd64.0.upload Date: Sat Jun 11 04:05:35 2016 DuplicateSignature: package:libapt-inst1.5:amd64:1.0.1ubuntu2.14:package libapt-inst1.5:amd64 is already installed and configured ErrorMessage: package libapt-inst1.5:amd64 is already installed and configured InstallationDate: Installed on 2016-06-10 (0 days ago) InstallationMedia: Ubuntu 14.04.4 LTS "Trusty Tahr" - Release amd64 (20160217.1) RelatedPackageVersions: dpkg 1.17.5ubuntu5.6 apt 1.0.1ubuntu2.14 SourcePackage: apt Title: package libapt-inst1.5:amd64 1.0.1ubuntu2.14 failed to install/upgrade: package libapt-inst1.5:amd64 is already installed and configured UpgradeStatus: No upgrade log present (probably fresh install) ** Affects: apt (Ubuntu) Importance: Undecided Status: New ** Tags: already-installed amd64 apport-package need-duplicate-check trusty -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1591479 Title: package libapt-inst1.5:amd64 1.0.1ubuntu2.14 failed to install/upgrade: package libapt-inst1.5:amd64 is already installed and configured To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/1591479/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs