package docker.io 1.13.1-0ubuntu1~16.04.2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Ronald Dicke]

May be same as two other listed bugs, not sure

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: docker.io 1.13.1-0ubuntu1~16.04.2
ProcVersionSignature: Ubuntu 4.13.0-38.43~16.04.1-generic 4.13.16
Uname: Linux 4.13.0-38-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
Date: Thu Apr 12 08:56:38 2018
DuplicateSignature:
 package:docker.io:1.13.1-0ubuntu1~16.04.2
 Setting up docker.io (1.13.1-0ubuntu1~16.04.2) ...
 addgroup: The group `docker' already exists and is not a system group. Exiting.
 dpkg: error processing package docker.io (--configure):
  subprocess installed post-installation script returned error exit status 1
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2018-02-13 (57 days ago)
InstallationMedia: Ubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.4
 apt 1.2.26
SourcePackage: docker.io
Title: package docker.io 1.13.1-0ubuntu1~16.04.2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #1749188, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.