several packages failed to install/upgrade: triggers looping, abandoned

Appeared as soon as the computer started

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: systemd 229-4ubuntu4 [modified: usr/share/dbus-1/system-services/org.freedesktop.systemd1.service]
ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6
Uname: Linux 4.4.0-21-generic x86_64
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
Date: Thu Apr 21 20:09:31 2016
ErrorMessage: triggers looping, abandoned
InstallationDate: Installed on 2015-11-23 (150 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M.
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-21-generic root=UUID=2faac09b-9252-4043-85b9-c6bfed793b7c ro quiet splash vt.handoff=7
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1
 apt 1.2.10ubuntu1
SourcePackage: systemd
SystemdDelta:
 [EXTENDED] /lib/systemd/system/rc-local.service → /lib/systemd/system/rc-local.service.d/debian.conf
 [EXTENDED] /lib/systemd/system/systemd-timesyncd.service → /lib/systemd/system/systemd-timesyncd.service.d/disable-with-time-daemon.conf
 [EXTENDED] /etc/systemd/system/display-manager.service → /lib/systemd/system/display-manager.service.d/xdiagnose.conf

 3 overridden configuration files found.
Title: package systemd 229-4ubuntu4 [modified: usr/share/dbus-1/system-services/org.freedesktop.systemd1.service] failed to install/upgrade: triggers looping, abandoned
UpgradeStatus: Upgraded to xenial on 2016-04-22 (0 days ago)
dmi.bios.date: 05/12/2015
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P2.20
dmi.board.name: Z97 Killer
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP2.20:bd05/12/2015:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnZ97Killer:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.