Could this be related to the core-14.30-14.31.sql (or other relevant SQL script) having run 'CREATE FUNCTION core.bulkImport' already? We've had a few issues over the years that involved the SQL upgrade scripts trying to create something that was already there and had similar looking errors. We use SQL Server, but core.bulkImport lives in Programmability->Stored Procedures. I'm assuming that \df in psql would show whether the core.bulkImport SP already exists.