Ubuntu software app does not open

[rowens66]

I updated from 14.4 to 16.4 on 4/2/2017 now ubuntu software app does not open. I click on app in launcher wait symbol shows but ubuntu software window does not open.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:16.04.21
ProcVersionSignature: Ubuntu 4.4.0-71.92-generic 4.4.49
Uname: Linux 4.4.0-71-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: Unity
Date: Mon Apr 3 11:51:16 2017
InstallationDate: Installed on 2017-04-02 (1 days ago)
InstallationMedia: Ubuntu 14.04.4 LTS "Trusty Tahr" - Release amd64 (20160217.1)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
Symptom: release-upgrade
UpgradeStatus: Upgraded to xenial on 2017-04-03 (0 days ago)
VarLogDistupgradeTermlog: