Removing faulty otrs

 sudo rm /etc/apache2/sites-available/otrs.conf

 sudo rm /etc/apache2/sites-enabled/otrs.conf

 sudo rm /home/$USER/.cache/software-center/piston-helper/rec.ubuntu.com,api,1.0,recommend_app,otrs,,81384ef50f6b1038436de465afd51202

 sudo rm /home/$USER/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,nl,any,any,any,otrs,page,1,helpful,,251358f9bbc99053ed71c6082e485827



 sudo rm /home/$USER/.cache/software-center/rnrclient/reviews.ubuntu.com,reviews,api,1.0,reviews,filter,nl,ubuntu,quantal,any,otrs,page,1,helpful,,7af23859b6e91926d3623a0d118dbf90



 sudo rm /var/cache/apt/archives/otrs2_3.1.7+dfsg1-5_all.deb 

 sudo rm /var/cache/apt/archives/otrs_3.1.7+dfsg1-5_all.deb 

 sudo rm /var/crash/otrs2.0.crash 

 sudo rm /var/crash/otrs2.0.upload 

 sudo rm /var/crash/otrs2.0.uploaded

just in case I missed something:

 sudo apt-get -y autoremove

 sudo apt-get -y clean

 sudo apt-get -y autoclean

 sudo apt-get -y check

 sudo dpkg --configure -a

 sudo apt-get install -f

Source:

• How to install the latest otrs - EuroBytes




• Bug #1154530 “package otrs2 3.1.7+dfsg1-5 failed to install/upgr...” : Bugs : “otrs2” package : Ubuntu