PostgreSQL 9.1 pg_restore error regarding PLPGSQL
It seems like pg_restore tries to restore some extra data which you don't own. Try to add -n public option to your pg_restore command line. It will tell pg_restore restore only contents of public schema. Your command line should looks like
pg_restore -U username -c -n public -d database_name
I found the following workaround on this page:
http://archives.postgresql.org/pgsql-general/2011-10/msg00826.php
The idea is to use pg_restore -l to list the contents of the archive, grep out the extension that the user doesn't have permission to restore, and use pg_restore -L to use this elided list when restoring.
For example:
pg_restore -l ~/database.dump | grep -v "EXTENSION - plpgsql" > ~/restore_elementspg_restore -L ~/restore_elements ~/database.dump
If you're running Postgres 11's (or higher) version of pg_dump then you can take advantage of the new --no-comments flag.