package ntop 3:5.0.1+dfsg1-2ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2

package ntop 3:5.0.1+dfsg1-2ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2

ProblemType: Package
DistroRelease: Ubuntu 14.04
Package: ntop 3:5.0.1+dfsg1-2ubuntu1
ProcVersionSignature: Ubuntu 3.16.0-45.60~14.04.1-generic 3.16.7-ckt14
Uname: Linux 3.16.0-45-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.11
AptOrdering:
 libucommon6: Install
 ucommon-utils: Install
 ntop: Configure
 libucommon6: Configure
 ucommon-utils: Configure
Architecture: amd64
Date: Thu Aug 20 22:40:50 2015
DuplicateSignature: package:ntop:3:5.0.1+dfsg1-2ubuntu1:subprocess installed post-installation script returned error exit status 2
ErrorMessage: subprocess installed post-installation script returned error exit status 2
InstallationDate: Installed on 2015-03-24 (152 days ago)
InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
SourcePackage: ntop
Title: package ntop 3:5.0.1+dfsg1-2ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2
UpgradeStatus: No upgrade log present (probably fresh install)