package samba4 4.0.0~alpha18.dfsg1-4ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 126

[Ravi Shankar Ganti]

ERROR: Invalid smb.conf
/var/lib/dpkg/info/samba4.postinst: 14: /var/lib/dpkg/info/samba4.postinst: /usr/share/samba/setoption.pl: Permission denied
dpkg: error processing samba4 (--configure):
 subprocess installed post-installation script returned error exit status 126
Processing triggers for libc-bin ...
ldconfig deferred processing now taking place
Errors were encountered while processing:
 samba4
E: Sub-process /usr/bin/dpkg returned an error code (1)

ProblemType: Package
DistroRelease: Ubuntu 12.04
Package: samba4 4.0.0~alpha18.dfsg1-4ubuntu2
ProcVersionSignature: Ubuntu 3.5.0-23.35~precise1-generic 3.5.7.2
Uname: Linux 3.5.0-23-generic i686
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: i386
Date: Mon Jun 3 15:00:07 2013
ErrorMessage: subprocess installed post-installation script returned error exit status 126
InstallationMedia: Ubuntu 12.04.2 LTS "Precise Pangolin" - Release i386 (20130213)
MarkForUpload: True
SourcePackage: samba4
Title: package samba4 4.0.0~alpha18.dfsg1-4ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 126
UpgradeStatus: No upgrade log present (probably fresh install)