package isc-dhcp-server 4.1.ESV-R4-0ubuntu5.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Adib]

1) Using Ubuntu 12.04
2) I just sudo apt-get update && sudo apt-get upgrade
3) I expected the upgrade installation process to be running without an error. but the , there is ...
4) instead, the i get the error like below...

mysql start/running, process 14736
Setting up mysql-server (5.5.24-0ubuntu0.12.04.1) ...
Setting up mysql-client (5.5.24-0ubuntu0.12.04.1) ...
Setting up isc-dhcp-common (4.1.ESV-R4-0ubuntu5.1) ...
Setting up isc-dhcp-server (4.1.ESV-R4-0ubuntu5.1) ...
Installing new version of config file /etc/init/isc-dhcp-server.conf ...
Installing new version of config file /etc/init/isc-dhcp-server6.conf ...
Installing new version of config file /etc/apparmor.d/usr.sbin.dhcpd ...
start: Job failed to start
invoke-rc.d: initscript isc-dhcp-server, action "start" failed.
dpkg: error processing isc-dhcp-server (--configure):
 subprocess installed post-installation script returned error exit status 1
Setting up isc-dhcp-client (4.1.ESV-R4-0ubuntu5.1) ...
dpkg: dependency problems prevent configuration of dhcp3-server:
 dhcp3-server depends on isc-dhcp-server; however:
  Package isc-dhcp-server is not configured yet.
dpkg: error processing dhcp3-server (--configure):
 dependency problems - leaving unconfigured
Processing triggers for menu ...
No apport report written because the error message indicates its a followup error from a previous failure.
                          Processing triggers for libc-bin ...
ldconfig deferred processing now taking place
Errors were encountered while processing:
 isc-dhcp-server
 dhcp3-server
E: Sub-process /usr/bin/dpkg returned an error code (1)

ProblemType: Package
DistroRelease: Ubuntu 12.04
Package: isc-dhcp-server 4.1.ESV-R4-0ubuntu5.1
ProcVersionSignature: Ubuntu 3.2.0-24.39-generic-pae 3.2.16
Uname: Linux 3.2.0-24-generic-pae i686
ApportVersion: 2.0.1-0ubuntu8
Architecture: i386
Date: Tue Jun 12 09:29:51 2012
DhServerLeases:

ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
ProcCmdline: BOOT_IMAGE=/boot/vmlinuz-3.2.0-24-generic-pae root=UUID=6a23a1b8-afec-4437-a15d-979393e158ed ro quiet splash vt.handoff=7
SourcePackage: isc-dhcp
Title: package isc-dhcp-server 4.1.ESV-R4-0ubuntu5.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.dhcp.dhcpd.conf: 2012-05-17T11:14:45.624667

[Stéphane Graber (stgraber)]

Please attach /var/log/upstart/isc-dhcp-server.log

[Christoph_vW (christoph-apiviewer)]

I have the same issue:

/var/log/upstart/isc-dhcp-server.log

The error was:
Internet Systems Consortium DHCP Server 4.1-ESV-R4
Copyright 2004-2011 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
/etc/dhcp/dhcpd.conf line 18: semicolon expected.
option
 ^

line 17 from /etc/dhcp/dhcpd.conf is missing the ";"

option subnet-mask 255.255.255.0