package ubuntu-mono 14.04+16.04.20160804-0ubuntu1 failed to install/upgrade: package ubuntu-mono is already installed and configured

[Alan Ostlund]

reistalled Ubuntu because of errors with thunderbird, K3B, slow downloads from random sites.

opened software center, tried to insall synaptic manager. Starts installing, never finishes, indicator is stopped at about 35%.

there is probably an error with the system, it gave me system error as soon as I booted up.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: ubuntu-mono 14.04+16.04.20160804-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-36.55-generic 4.4.16
Uname: Linux 4.4.0-36-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
AptdaemonVersion: 1.1.1+bzr982-0ubuntu14
Architecture: amd64
Date: Wed Sep 7 07:40:10 2016
DuplicateSignature:
 package:ubuntu-mono:14.04+16.04.20160804-0ubuntu1
 Processing triggers for hicolor-icon-theme (0.15-0ubuntu1) ...
 dpkg: error processing package grub-pc (--configure):
  package grub-pc is already installed and configured
ErrorMessage: package ubuntu-mono is already installed and configured
InstallationDate: Installed on 2016-09-07 (0 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.12~ubuntu16.04.1
SourcePackage: dpkg
Title: package ubuntu-mono 14.04+16.04.20160804-0ubuntu1 failed to install/upgrade: package ubuntu-mono is already installed and configured
UpgradeStatus: No upgrade log present (probably fresh install)