Forum OpenACS Q&A: Re: createlang step
debian:~# su postgres -c "/usr/lib/postgresql/bin/createlang plpgsql template1"
sometimes didn't work to me as well. then i just log as postgres and execute createlang.
postgres:~# createlang plpgsql template1
and it worked out.
also as dave said. make sure postmater service is up!