Forum OpenACS Q&A: Response to System and anon users not loaded on fresh ACS/PG install?

aha! There you go. Your shared library for PLPGSQL is not found. You need to look in www/doc/sql/postgres.sql and find the lines that create the plpgsql language, and make sure the paths are correct with respect to your Postgres installation.

Destroy the db, fix postgres.sql for your system, and try again.