package libnm-glib-vpn1:i386 1.2.6-0ubuntu0.16.04.3 failed to install/upgrade: package is in a very bad inconsistent state; you should reinstall it before attempting configuration

[Leo Germeys]

the installing gui 'Ubuntu Software' is repeatedly outphased in X revealing instability somewhere. Ubuntu 16.04.5 LTS is the output from lsb_release -rd. As a result I had to restart installation for updates several times.
Such disfunctioning occured a number of times before with the gui, so I was using apt instead, but as it was stated that the gui would be improved, I gave it a try.
It showed a large number of errors. Moreover it does not show any progress of what is going on during install of updates.
In the small window it was stated that libnm-glib-vpn1:i386 would be in total bad shape so it should be removed and reinstalled. This is now done. But that seems only the result of an instability occuring lately quite often with Ubuntu, starting with some larger uodate a couple of months ago.
I know this is not a very precise description. I will now clean up the system starting with verifying all packages. The instability will probably remain though.
In the process the gui was also updated and seems now to be functioning, so the version is now
ubuntu-software 3.20.5-0ubuntu0 i386 .
There are similar issues of being outphased with libreoffice, evince and probably some more which we seldom use.
The common link between these errors is that contact with X is temporarily lost while free memory is low.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: libnm-glib-vpn1:i386 1.2.6-0ubuntu0.16.04.3
ProcVersionSignature: Ubuntu 4.4.0-140.166-generic 4.4.162
Uname: Linux 4.4.0-140-generic i686
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: i386
Date: Fri Dec 14 15:49:36 2018
DuplicateSignature:
 package:libnm-glib-vpn1:i386:1.2.6-0ubuntu0.16.04.3
 Processing triggers for hicolor-icon-theme (0.15-0ubuntu1.1) ...
 dpkg: error processing package libnm-glib-vpn1:i386 (--configure):
  package is in a very bad inconsistent state; you should
ErrorMessage: package is in a very bad inconsistent state; you should reinstall it before attempting configuration
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2017-08-25 (476 days ago)
InstallationMedia: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release i386 (20140722.2)
IpRoute:
 default via 192.168.0.1 dev wlan0 proto static metric 600
 169.254.0.0/16 dev wlan0 scope link metric 1000
 192.168.0.0/24 dev wlan0 proto kernel scope link src 192.168.0.103 metric 600
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.5
 apt 1.2.29
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: network-manager
Title: package libnm-glib-vpn1:i386 1.2.6-0ubuntu0.16.04.3 failed to install/upgrade: package is in a very bad inconsistent state; you should reinstall it before attempting configuration
UpgradeStatus: Upgraded to xenial on 2017-08-25 (476 days ago)
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH
 wlan0 wifi connected /org/freedesktop/NetworkManager/Devices/2 dlink-5C98 af76c1cc-4c5d-4991-af25-a2fdfd7a5b5c /org/freedesktop/NetworkManager/ActiveConnection/0
 eth0 ethernet unavailable /org/freedesktop/NetworkManager/Devices/1 -- -- --
 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/0 -- -- --
nmcli-nm:
 RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
 running 1.2.6 connected started full enabled enabled enabled enabled enabled