Nominatim import problem: unable to start pgsql

While importing the planet files into Nominatim, I encounter the following error below. The import command used is ./setup.php --osm-file us-northeast.osm.pbf --all

I have been following the Nominatim installation instructions here.

Problem:

Create DB
Setup DB
createlang: language "plpgsql" is already installed in database "nominatim"
unable to start pgsql

I have already disabled open_basedir using WHM. Any suggestions on what to do next? Thanks!