package libapache2-mod-svn 1.9.7-4ubuntu1 failed to install/upgrade: installed libapache2-mod-svn package post-installation script subprocess returned error exit status 1

[sudhish]

<Location /svn>
     DAV svn
     SVNParentPath /opt/svn
     AuthType Basic
     AuthName "Subversion Repository"
     AuthUserFile /etc/apache2/dav_svn.passwd
     Require valid-user
</Location>

these are the changes done to dav_svn.conf

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: libapache2-mod-svn 1.9.7-4ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-30.32-generic 4.15.18
Uname: Linux 4.15.0-30-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
Date: Tue Aug 7 11:11:52 2018
ErrorMessage: installed libapache2-mod-svn package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2018-07-19 (21 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
Python3Details: /usr/bin/python3.6, Python 3.6.5, python3-minimal, 3.6.5-3ubuntu1
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2
 apt 1.6.3
SourcePackage: subversion
Title: package libapache2-mod-svn 1.9.7-4ubuntu1 failed to install/upgrade: installed libapache2-mod-svn package post-installation script subprocess returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.apache2.mods-available.dav_svn.conf: 2018-08-07T11:24:48.688174