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

I have no idea what the problem. I am kind of a noob, but when I tried installing it. This error poped up.

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: Wed Sep 17 19:50:37 2014
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)